What Is Vomma? The Convexity of Vega
Vomma is the rate of change of an option's vega as implied volatility moves. See where it peaks on the strike ladder, measured on a real SPY option chain.
Learn
Evergreen explainers of how US markets actually work, each concept taught with real, queryable market data.
Block Trade Discounts and Bought Deals
Why block trade discounts exist: how a bank prices a bought deal overnight, what sets the size of the discount, and how the print lands on the tape.
Does the PDT Rule Apply to Crypto and Futures?
Does the PDT rule apply to crypto or futures? No. It is a FINRA margin rule on securities accounts. Here is what governs each asset class instead.
Is There a Minimum Holding Period for Stocks?
There is no minimum holding period for stocks. You can sell seconds after buying. Four clocks, settlement, day trades, dividends and wash sales, set the cost.
US Premarket and After-Hours in Israel Time
US premarket opens 11:00 Israel time and after hours runs to 03:00. The full session table, UTC offsets, and the weeks the two clock rules fall out of step.
Trading API vs Market Data API: Key Differences
A trading API acts on your brokerage account; a market data API answers price questions under exchange licensing. Where the line sits, and which one you need.
US Dividend Frequency: Quarterly vs Japan
US dividend frequency is quarterly, while most Japanese companies pay twice a year. Here is the four-date payment calendar and the monthly exceptions.
Do Multi-Leg Options Count as One Day Trade?
Do multi-leg options count as one day trade? How brokers tally a four-leg condor closed as a package versus leg by leg, and where to check your own counter.
What Is the Term Premium in Bond Yields?
The term premium is the piece of a 10 year Treasury yield left over after expected short rates. See the split on the live curve, and why it is an estimate.
Can You Lose More Than You Invest?
Can you lose more than you invest? Cash stock floors at zero. Margin debits, short sales, short options and futures each remove that floor, with data.
What Price Does a Market Order Fill At?
A market order fills at whatever the book gives: usually the far side of the NBBO, sometimes better, sometimes three levels worse. Here is the tape.
Can You Cancel a Limit Order Before It Fills
Can you cancel a limit order? Usually yes, but a cancel is a request that races the fill. Here are the four outcomes you will meet and what decides each one.
Can You Opt Out of Share Lending?
Can you opt out of share lending? Yes in a cash account or a fully paid program, usually not on margin. The two levers, and the tax on a payment in lieu.
Protective Put vs Stop-Loss Order
Protective put vs stop-loss order on one 100-share position: how each sets a floor, what an overnight gap does to a stop, and what the put premium costs.
Why a Limit Order Didn't Fill: 5 Causes
The tape printed your price and your order is still open. Here are the five reasons a limit order didn't fill, in order of how often each one happens.
Buy Limit vs Sell Limit Orders Explained
Buy limit vs sell limit orders: a buy limit is a ceiling at or below the market, a sell limit is a floor at or above it. See all four cases on one quote.
VOO Dividend: Ex-Dividend Dates & Yield
VOO dividend: the latest declared ex-dividend date, the trailing twelve month payout per share, the yield it works out to, and why the calendar is an estimate.
Micro Gold Futures vs GLD: Size, Tax, Cost
Micro gold futures vs GLD: one MGC covers 10 ounces, about 109 GLD shares. Compare tick value, margin, the 0.40% fee and the 60/40 vs 28% tax split.
Event-Driven vs Vectorized Backtesting
Event-driven vs vectorized backtesting, settled with data: what the same-bar fill costs in index points, and the three things only an event loop can model.
Which ETFs Have 0DTE Options?
Which ETFs have 0DTE options? We count every dated expiration in the option chain, by weekday, and rank the funds by how many weekdays they cover.
SPYM Dividend: Ex-Dividend Dates & Yield
SPYM dividend data: the declared, ex-dividend, record and pay dates each quarter, plus the trailing 12 month payout per share and the yield it works out to.
US Dividend Tax for Japanese Investors
US dividend tax for Japanese investors: the 10% treaty rate, the W-8BEN behind it, Japan's 20.315% layer, and why NISA turns the 10% into a dead loss.
PG Dividend 2026: Dates, History and Yield
Every 2026 PG dividend date: declaration, ex dividend, record and payment, with the quarterly amount, the annual raise and a trailing yield you can check.
Marketable vs Non-Marketable Limit Orders
A marketable limit order fills now at a capped price; a non-marketable one rests in the book. See the split at the NBBO with real quote and fill data.
Most Active Stocks After Hours: How It Works
How most active stocks after hours lists are actually built: which prints count between 4 and 8 p.m. ET, and why two screeners name different leaders.
How Stock Splits Get Announced: 8-K to Ex-Date
How stock splits are announced: the board vote, the press release and 8-K filing, then the exchange notice. Plus the typical gap to the effective date.
ETF vs Mutual Fund Settlement: Two Clocks
ETF vs mutual fund settlement, side by side: when each trade date starts, what price you get, and the exact day the cash is withdrawable under T+1.
Open-Source Trading Terminal for Python
What an open-source trading terminal for Python really is: where an agentic IDE sits between a notebook, a backtester and a live broker, and what it cannot do.
Who Matches Overnight US Stock Trades?
Who matches overnight US stock trades? The single ATS behind the 8 p.m. to 4 a.m. session, and why no NBBO protects your resting limit order at 2 a.m. ET.
Why Stop Orders Fill Below Your Stop
Why stop orders fill below your stop price: the trigger becomes a market order, and overnight gaps, fast markets, halts and thin sessions set the fill.
Market Data Licensing for App Developers
Market data licensing for app developers, explained: entitlement, redistribution and display, what delayed feeds allow, and a pre-ship compliance checklist.
When Do NDX Options Expire?
NDX options expire on the third Friday, AM settled from the opening prints, and stop trading the Thursday before. Every remaining 2026 date is listed.
China's Dragon-Tiger List, Explained
What is China's dragon-tiger list? After each close, Shanghai and Shenzhen name the top buying and selling brokerage branches. What it can and cannot show.
Does Canada Have After-Hours Trading?
Does Canada have after-hours trading? The TSX runs a 4:15 to 5:00 p.m. ET last sale session, with no price discovery. Here is how it differs from the US.
AMZN Premarket and After-Hours Prices
Where AMZN premarket and after-hours prices come from, which hours they cover, and why two brokerage screens show different numbers on an earnings night.
Why Would Anyone Sell a Put Option?
Why would anyone sell a put option? The premium is payment for a real obligation. Where a high win rate hides a deep tail, and when selling is a bad idea.
Walmart Stock Split History (WMT)
Walmart stock split history in full: every WMT ratio and effective date, the cumulative adjustment factor, and how many shares one early share became.
What Is GMP in an IPO? Grey Market Premium
GMP in an IPO is the grey market premium: an unofficial, unsettled quote on an unlisted issue. What it measures, and how widely listing-day moves actually run.
Do NYSE and Nasdaq Have Public APIs?
Do NYSE and Nasdaq have public APIs? What each exchange really publishes, who can access real time quotes, what it costs, and the license rules behind it.
What Determines an Option's Price?
What determines an option's price? Five inputs you can look up, plus volatility. We reprice one real AAPL call and rank each input by dollars. See the ranking.
Payout Ratio Over 100%: What It Means
A payout ratio over 100% means dividends exceeded earnings. The four reasons it happens, and how the same ratio on free cash flow tells them apart.
Stop Order vs Limit Order: Trigger or Price
Stop order vs limit order, explained: a stop is a trigger that becomes a market order, a limit is a price ceiling or floor. Worked fills for each, with data.
How Are Event Contracts Taxed? 60/40 or Not
How are event contracts taxed? Compare Section 1256 60/40 treatment with ordinary income and wagering rules, plus which tax form the venue sends in 2026.
ZM Implied Volatility: Zoom IV and Earnings
ZM implied volatility, measured from traded Zoom option contracts: the current 30 day at the money level, its percentile, earnings crush, and term structure.
Which Options Expire on Each Weekday
A weekday by weekday map of options expirations: what expires Monday through Friday, and how to check any chain yourself for a weekday you do not see listed.
Do Stock Splits Need Shareholder Approval?
Do stock splits need shareholder approval? Most forward splits need more authorized shares first, and that charter vote is what sets the announcement gap.
Tape A, B, and C Explained: CTA and UTP
Tape A, B, and C explained: how a stock's listing venue sets its tape, which SIP plan publishes it, and how to tell which tape a symbol trades on.
US Premarket and After-Hours in UK Time
US premarket and after-hours in UK time, from the 9:00am BST premarket open to the 1:00am close, plus the autumn weeks when the gap drops to four hours.
When Do VIX Futures Expire? 2026 Dates
VIX futures expire on the Wednesday 30 days before the next month's third-Friday SPX expiry. Every 2026 settlement date, plus the walk-back arithmetic.
VZ Dividend 2026: Dates, Payout and Yield
VZ dividend 2026: every declared Verizon ex-dividend, record and payment date, the per share rate beside each, plus the current yield on a dated close.
SPY ETF Price in Korean Won: KRW per Share
What does one share of SPY cost in Korean won? Work the conversion yourself with today's USD close, your broker's FX spread, and the 22:30 KST clock.
PEP Dividend 2026: Ex-Dates and the Raise
PEP dividend 2026 dates in one table: PepsiCo's next ex-dividend date, all four quarterly payments, the February raise, and the 2026 per share total.
JNJ Dividend 2026: Dates, Raise and Yield
Every JNJ dividend in 2026: declaration, ex-dividend, record and payment dates, the April raise, the quarterly rate, and the yield on 2026 prices.
How to Invest in the DAX: Which Index You Get
Before you invest in the DAX, check which DAX: the headline index reinvests dividends, the Kursindex does not. Compare ETF, futures and Xetra routes.
ES Futures Trading Hours and the Daily Break
ES futures trading hours in CT and ET: the Sunday 5 p.m. open, the 4 p.m. maintenance break, and why the old 3:15 p.m. equity index halt no longer applies.
Is the US Market Open on Japanese Holidays?
Is the US market open on Japanese holidays? Yes: the NYSE and Nasdaq ignore the TSE calendar. What still stalls is JPY settlement and FX conversion.
ASX Options Expiry and Settlement Explained
ASX options expiry falls on a Thursday, and ASX 200 index options cash settle against the opening price calculation. The dates and the Sydney cut off times.
What Exchange Colocation Costs Per Month
What exchange colocation costs per month: cabinet, power, cross connects, ports and entitlements, with every figure pinned to a dated public fee schedule.
Partial Assignment of Short Options
Partial assignment happens when only some of your short options are exercised. See how the OCC and your broker allocate, and what the leftover stub means.
Free Stock API With curl and jq: No Key
Call a free stock market API from the shell: install curl and jq on Ubuntu, read the JSON, filter rows with jq, and export clean CSV. No key needed.
SPY Dividends for Korean Investors
SPY dividends for Korean investors: the quarterly ex-date and payment cycle, the US treaty withholding rate, Korean financial income tax, and the KST offset.
Buying Puts vs Buying Calls: Why Puts Cost More
Buying puts vs buying calls is not a mirror trade. Skew, carry and realised volatility make the put the pricier side. Four measured reasons, with data.
US Stock Market Hours in UAE Time (GST)
US stock market hours in UAE time: the 09:30 to 16:00 ET session runs 17:30 to 00:00 GST in US summer and 18:30 to 01:00 GST in winter, plus premarket.
Recent Reverse Stock Splits: Last 90 Days
Every recent reverse stock split effective in the past 90 days, with ticker, ratio and effective date, plus how to tell a 1-for-10 from a 10-for-1.
PFE Dividend 2026: Ex-Dates and Payments
The PFE dividend 2026 calendar: declaration, ex-dividend, record and pay dates with the per share amount, the yield math, and the next ex-date ahead.
How DAX Index Weights Are Calculated
How DAX index weights are calculated: free float market cap, the 10 percent single stock cap, quarterly reviews, and why the headline chart includes dividends.
Why Only Some Stocks Have Daily Options
Why only some stocks have daily options: the listing rules, liquidity thresholds and quote width math that keep Monday through Friday expirations rare.
Mutual Fund Exchange vs Selling and Rebuying
A mutual fund exchange prices both legs at one 4 p.m. NAV, while selling at one firm and rebuying at another adds settlement days. Two Monday timelines.
Iron Condor Screener from the SQL API
How to build an iron condor screener in SQL from daily options greeks, ranked by IV percentile, with a check on how many candidates still clear a week later.
How Often Mutual Funds Change Holdings
How often do mutual funds change holdings? What the portfolio turnover ratio measures, and how many days old the holdings list on a fund page usually is.
How Many Puts to Hedge a Portfolio: Formula
How many puts to hedge a portfolio? The contract formula worked through at the same index level for SPX, XSP and SPY, with rounding and cost in dollars.
Can You Buy a Put Without Owning Stock?
Can you buy a put without owning the stock? Yes, and here is how the plain long put differs from a protective put and from shorting shares, with option prices.
How Exchange Speed Bumps Work
How exchange speed bumps work: which messages a 350 microsecond delay holds back, what it does to queue position, and when the quote stays protected.
Micro E-mini vs E-mini Futures: Specs & Cost
Micro E-mini vs E-mini futures compared: multiplier, tick value, notional and the commission math that decides where the micro premium actually lands.
AAPL Dividend 2026: Dates and Amounts
Apple's AAPL dividend 2026 schedule: declaration, ex-dividend, record and pay dates for every quarter, the per share amount, and the yield on a dated close.
What Happens When an ETF Closes
What happens when an ETF closes: the closure announcement, the last trading day, the cash liquidating distribution at NAV, and the taxable event it creates.
Substitute Payments and Your 1099
Substitute payments land in box 8 of Form 1099-MISC and are taxed as ordinary income. See the dollar tax gap and which brokers add a gross up credit.
SPLG Is Now SPYM: What Changed for Holders
SPLG is now SPYM. State Street renamed its low cost S&P 500 ETF on 31 October 2025, and for holders only the symbol and the fund name actually changed.
Mutual Fund Cutoffs on Early-Close Days
Mutual fund cutoffs move on early-close days: when the NYSE closes at 1:00 p.m. ET, forward pricing strikes NAV early and every broker deadline shifts.
Tradegate vs Xetra: Hours and Prices
Tradegate trades to 22:00 CET while Xetra closes at 17:30. Compare the hours, see which venue sets the official price, and why two quotes can differ.
Why Overnight Orders Must Be Limit Orders
Overnight orders must be limit orders. In the 8 p.m. to 4 a.m. ET session there is no consolidated quote to protect a print, and a book one order can sweep.
What Is the TTM Squeeze? Formula and Limits
The TTM Squeeze fires when Bollinger bands contract inside the Keltner channel. Here is the exact formula, and the settings that make two charts disagree.
FINRA Short Volume Ratio by Ticker
Compute the FINRA short volume ratio by ticker from the daily RegSHO files using curl and awk on one pinned date, and learn what the ratio does not measure.
Does an Expired Option Count as a Day Trade?
Does an expired option count as a day trade? Expiration is not a transaction you place, so it does not add to the count. The cases that do, explained.
Overnight Trading Order Types: Limit Only
Overnight trading order types, explained: why the session is limit only at most brokers, and how time in force behaves on an order resting at 2 a.m.
RSP vs SPY: Equal Weight S&P 500
RSP vs SPY: there is no equal weighted SPY. See how much of cap weighted exposure sits in the top names, and what the quarterly rebalance changes.
What Stocks Are in the DAX 40?
What stocks are in the DAX 40? The full member list as of September 2026, plus the free float weighting, the 15 percent cap and the rules for joining.
How VIX Settlement Works: the SOQ
VIX settlement uses the SOQ, a Special Opening Quotation built from SPX opening prices under a zero bid strike rule. How the print is made, and why it gaps.
US Market Hours in German Time (CET/CEST)
US market hours in German time: the NYSE session in CET and CEST, the Xetra overlap window, and the few weeks each year when the clock gap shrinks.
Has SPY Ever Split? The ETF Split Record
Has SPY ever split? The split record says no. Here is why an ETF share price is set by its sponsor at launch, and what a split would actually change for you.
When Do Index Funds Trade? ETFs vs Mutual Funds
When do index funds trade? An index ETF prices all day like a stock. An index mutual fund does not trade intraday: it fills at the NAV after 4 p.m.
Accenture (ACN) Dividend History and Raises
Accenture (ACN) dividend history: every declared, ex, record and pay date on record, the size of each annual raise, and what a payout ratio tells a reader.
Honeywell (HON) Dividend History by Year
Honeywell dividend history in one table: every HON declaration with ex, record and pay dates, the raise size each year, and the usual announcement month.
The 10:00 AM Rule in Stocks, Tested
The 10:00 AM rule says wait out the opening 30 minutes. We tested it on three years of minute bars: how much range and volume the open really puts in.
US Stock Market Hours in Singapore Time
US stock market hours in Singapore time: the New York session opens 21:30 or 22:30 SGT depending on US daylight saving. Full SGT clock, plus holidays.
The $100,000 Rule for Stock Options (ISOs)
The $100,000 rule for stock options caps how much ISO stock can first become exercisable in one calendar year. How the limit works, with the paperwork.
Stocks With the Highest Option Premiums
Which stocks have the highest option premiums? A dollar ranking is a share price ranking. Rank by percent of strike instead, with the liquidity filters.
Relative Volume Screener in SQL: Free API
Build a relative volume screener in SQL, with the time of day correction the RVOL formula needs, one curl call, no API key, and a ranked top 20 list.
Mutual Fund Order Cutoff Times by Broker
Mutual fund order cutoff times by broker: why 4:00 p.m. ET is the default, which funds stop earlier, and when to submit an order for today's closing NAV.
How QQQ Holdings Are Weighted, and Capped
How QQQ holdings are weighted: the Nasdaq-100 uses modified market cap weighting with capping rules at every rebalance. The thresholds, dates and data.
Ex-Dividend Date: Open Orders and Premarket
What happens to a resting buy limit when a stock goes ex-dividend, which open orders get reduced, and why premarket can look down before the open.
Crypto Covered Call ETFs: Yield Explained
Crypto covered call ETFs advertise huge distribution rates. Here is what they hold, where the premium comes from, and what the capped upside costs you.
XOM Dividend Increase History: Every Raise
Every XOM dividend increase on record: old and new quarterly rate, the percentage raise, the quarter Exxon declares in, and 5, 10 and 20 year growth.
Weekly Dividend ETFs: How the Payouts Work
Weekly dividend ETFs pay every week from call option premium rather than portfolio dividends. Where the cash comes from, and what it does to the price.
US Stock Market Hours in Mountain Time
US stock market hours in Mountain Time: 7:30 a.m. to 2:00 p.m. in Denver all year, 6:30 a.m. in most of Arizona each summer. Live session data inside.
Stock Splits in Japan and the 100-Share Unit
Stock splits in Japan are ticket size housekeeping: Tokyo trades in units of 100 shares. Here is the unit arithmetic and how the US and India differ.
Mutual Fund Forward Pricing Rule Explained
Under the forward pricing rule, a mutual fund order is priced at the next NAV struck after it arrives. Here is what that means for your buy or sell.
How Much Does One Share of Stock Cost?
How much does one share of stock cost? Prices run from under a dollar to six figures. Here is the full price ladder, the median share price, and what sets it.
Ex-Dividend Dates on the ASX: Rules & Timing
How ASX ex-dividend dates work: the ex date sits one business day before the record date, plus franking credits and the 45 day holding period test.
What Does Historical Tick Data Cost?
Historical tick data is priced on four axes: venue, schema, volume delivered, and license type. Here is how each axis works, with real record counts.
Why Open Interest Updates Only Once a Day
Open interest updates once a day, after overnight clearing. See why the OI column you read at noon is yesterday's number, and what volume shows instead.
Stock Split Calendar From a Free SQL API
Build a stock split calendar with one curl call and one SQL query: upcoming forward and reverse splits, ratios, effective dates, and splits per month.
KRX After-Hours Trading: Korea's Sessions
KRX after-hours trading explained: the closing price windows, the new 4 p.m. to 8 p.m. after market, which price each order gets, and the KST to ET shift.
Do Mutual Funds Trade on Market Holidays?
Mutual funds do not trade on market holidays: no NAV is struck, orders queue to the next cutoff, and an early close moves the 4 p.m. pricing to 1 p.m.
When Do SPX Options Stop Trading?
SPX options stop trading on two clocks: the AM settled monthly ends its session on Thursday, while SPXW weeklies run into Friday. Both cutoffs, with data.
Covered Call Screener: Build One in SQL
Build a covered call screener in SQL: rank a whole option chain by annualised premium yield inside a delta band, then replay the screen on past dates.
DAX Futures Explained: FDAX, FDXM, FDXS
DAX futures trade on Eurex in three sizes. Compare FDAX, FDXM and FDXS on index point multiplier, tick value in euros, notional and cash settlement.
Ex-Dividend Calendar from a Free SQL API
Build a forward ex-dividend calendar with one curl call to a free SQL API, plus the jq one liner that shapes the next 14 days into a readable table.
Can You Use a Limit Order on a Mutual Fund?
A mutual fund order ticket has no price box: every buy and sell strikes at the next computed NAV. What a limit order cannot do, and the two levers you have.
After-Hours Trading on Holidays and Weekends
Is after-hours trading open on holidays or weekends? What runs on a 1:00 p.m. early close, why Saturday is dark, and how to check any date yourself.
Stock Splits in India: Face Value Explained
An Indian stock split is announced as a face value cut, ₹10 to ₹2, which is the same event a US filing calls 5-for-1. Read the dates and the mechanics.
Covered Calls on Futures: How They Work
Covered calls on futures have no shares to cover: assignment hands you an offsetting short future, and SPAN margins the package. See how the numbers work.
Can German Retail Investors Short Stocks?
Can German retail investors short stocks? Share borrowing is rare at German brokers, so shorting runs through CFDs, knock-outs, warrants and inverse ETFs.
Eurex Option Codes: ODAX, ODAP, OESX
Eurex option codes explained: ODAX and ODAP on the DAX, OESX and OEXP on the EURO STOXX 50, with the contract value and settlement style for each line.
Do Mutual Funds Trade in the Primary Market?
Mutual fund shares are issued and redeemed by the fund itself, so every buy and sell is a primary market trade at the next NAV. Here is how that works.
SPX Options vs ES Futures Options: Which to Use
SPX options vs ES futures options, side by side: $100 vs $50 a point, cash vs futures settlement, SPAN 2 vs Reg T margin, 23-hour sessions and 60/40 tax.
MSFT Dividend 2026: Dates, Raise, Per Share
MSFT dividend 2026: every ex-date, record and pay date, the September raise history since 2020, yield at the latest close, and per-share totals two ways.
How Pre-IPO Shares Trade Before the Ticker
How pre-IPO shares trade before the ticker: private platforms, tender offers, DXYZ's premium to NAV, tokens, perpetual futures, and why none is the IPO price.
Best Stocks for Day Trading Options (Ranked)
Which stocks are best for day trading options? The most liquid names ranked by 20-session contract volume, with spread, 30-day IV and daily expiration data.
Is Cross Trading Legal? Rules by Venue
Is cross trading legal? Yes, by rule: Reg NMS for exchanges, FINRA 5320 for brokers, Rule 17a-7 for funds, CME Rule 539 in futures. Plus the wash-trade line.
US Stock Market Hours in London Time (BST/GMT)
US stock market hours in London time: the NYSE opens at 14:30 and closes at 21:00 for most of the year, moving to 13:30 for a few weeks each spring and autumn.
How Treasury Buybacks Work (and Why Not QE)
How Treasury buybacks work: the two operation types, who can offer, how offers are accepted, why a buyback is not QE, and how to pull results from FiscalData.
Stock Repair Strategy: A Real NKE Example
The stock repair strategy priced on a real NKE chain: which short strike makes the 1x2 call ratio free, and how far the breakeven drops versus hold and hope.
Risk Reversal Options: Sell a Put, Buy a Call
A risk reversal sells an out-of-the-money put to fund an out-of-the-money call. One AAPL chain priced at 25 delta, its payoff and the skew spread desks quote.
What Is a Liquidity Heatmap? How to Read One
A liquidity heatmap paints resting order size at every price level over time. It needs depth-of-book data, not Level 1, and it only shows displayed orders.
US Stock Market Hours in Sydney Time
US stock market hours in Sydney time: NYSE opens at 23:30 AEST, 00:30 or 01:30 AEDT by season. All 2026 and 2027 changeover dates, holidays and pre-market.
Upcoming Reverse Stock Splits: Live Calendar
Which stocks reverse split next? Every upcoming reverse stock split with ratio and effective date, plus the monthly count of reverse versus forward splits.
EURO STOXX 50 Daily Options (OEXP) Explained
What EURO STOXX 50 daily options (OEXP) are: EUR 10 per point, cash settled on the 17:30 CET close, ten daily expiries, and where that lands in US hours.
Can You Cancel a Mutual Fund Order? 4 pm Cutoff
You can cancel a mutual fund order until the fund's cutoff, usually 4 pm ET. After that it fills at the day's NAV and cannot be undone, even before settlement.
What Is a Liquidity Sweep in Trading?
A liquidity sweep is price pushing through a prior high or low where stop orders cluster, then reversing. What the tape shows, and base rates for SPY and QQQ.
NYSE Closing Auction Explained: How It Works
How the NYSE closing auction sets the official close: the DMM's role, the 3:50 p.m. MOC and LOC cutoff, Closing D Orders at 3:59:50, and a real closing print.
Can You Make $1,000 a Day Day Trading?
Can you make $1,000 a day day trading? The return each account size needs, set against the daily ranges SPY, QQQ, NVDA and TSLA offered from 2021 to 2025.
How to Download FINRA Daily Short Volume Data
Fetch FINRA daily short volume data with curl, read the Reg SHO file's columns, and compute a symbol's short volume ratio with awk. Pinned date, reproducible.
Market-Wide Circuit Breakers Explained
Market-wide circuit breakers halt all US stock trading at 7%, 13% and 20% S&P 500 drops. See today's SPY trigger levels and the four March 2020 halts.
How Long Can a Stock Trade Under $1? The Rules
How long can a stock trade under $1? The Nasdaq and NYSE delisting clocks, the 2025 rule changes, why reverse splits often fail, and today's sub-$1 count.
Free Stock Market Data API in Python
Call a free stock market data API in Python with requests and pandas: an Ubuntu tutorial that loads JSON into a DataFrame and prints 20-day average volume.
What Are Tokenized Stocks? Rights & Settlement
What are tokenized stocks? How an on-chain record of a share works, which rights carry over, what changes at settlement, and what the SEC's 2026 order allows.
Nasdaq Opening Cross Explained: 4 a.m. to 9:30
How the Nasdaq opening cross sets the 9:30 a.m. open: the 4:00 a.m. to 9:30 timeline, MOO, LOO and OIO cutoffs, the NOII feed, and how the price is picked.
The September Effect: Is It Real? SPY Data
Is the September effect real? We count every SPY September on record: average and median return, hit rate, the three worst years, and a split by decade.
Where to Find Options Trade Data (OPRA Prints)
Where to find options trade data: OPRA prints, free broker time and sales, per-contract APIs from Massive, Databento and ThetaData, and what a print carries.
Are 0DTE Options High Risk? What the Greeks Say
Are 0DTE options high risk? Gamma and theta per dollar of premium for a same-day SPY contract versus a month-out one, and how far SPY must move to double it.
How Much Money Do You Need to Trade Options?
How much money you need to trade options at each approval level: cash accounts, the $2,000 margin floor, spread collateral, naked put margin and the PDT line.
What Is the CME CVOL Index? CVOL vs VIX
The CME CVOL index measures 30-day implied volatility in futures options using simple variance and equal strike weights. Here is how it differs from VIX.
What Is the 3m10y Spread? The Fed's Yield Curve
The 3m10y spread is the yield curve behind the New York Fed's recession model. Twenty years of readings, every inversion since 1985, and where it sits now.
Buy on the Ex-Dividend Date: Do You Get Paid?
Buy on the ex-dividend date and you do not get the dividend: a T+1 trade settles after the record date and the seller keeps it. Real Apple dates inside.
TWAP vs VWAP vs POV Orders Explained
TWAP vs VWAP vs POV orders: how each execution algorithm slices a trade, why VWAP front loads around the open, and what a 10% POV order does at lunch.
What Does Cross Mean in Trading? 4 Meanings
In trading, cross means four things: the opening and closing cross auctions, a broker's cross trade, a crossed market, and chart crosses. Here is each one.
Santa Claus Rally: Hit Rate and Returns by Year
The Santa Claus rally, measured year by year from SPY: the seven-session window, its hit rate, mean and median return, the worst windows, and what followed.
The 390 Rule in Options: Professional Status
The 390 rule: average over 390 options orders a day in a month and exchanges treat you as a Professional. What brokers count and what changes in practice.
The 7-5-3-1 Rule in Mutual Funds, Tested
What the 7-5-3-1 rule for SIPs actually says, and a test of its 7-year claim against rolling seven-year S&P 500 returns, with the step-up arithmetic shown.
How to Store Market Data PCAPs: Split, Compress
How to store market data PCAPs: build a capture with text2pcap, split it with editcap, then measure gzip, xz and zstd on one file to size a retention plan.
Nasdaq Closing Cross Explained: NOII and MOC
How the Nasdaq closing cross works: MOC and LOC cutoffs, imbalance-only orders, the NOII feed from 3:50 p.m., and one real 4:00:00 print read off the tape.
When Do VIX Options Expire? The Wednesday Rule
VIX options expire on Wednesdays and stop trading the Tuesday before. They settle in cash to the SOQ rather than the spot VIX. All 2026 monthly dates inside.
How to Get Approved for Options Trading
How to get approved for options trading: what the options application asks under FINRA Rule 2360, how brokers score your answers, and honest ways up a level.
What Is a High VIX? Levels and Extremes
What is a high VIX? A level ladder from under 15 to over 40, the daily S&P 500 move each implies, how rare each has been, and the record extremes by date.
Short Delivery Auction in India: NSE Rules
Short delivery auction in India, explained: what NSE does when a seller fails to deliver under T+1, the 2:30 pm session, the 20% band and the close-out rule.
Dividend Increases Expected This Month
Dividend increases expected this month: companies that raised in each of the last five years and announced in this month, split into declared and pending.
Why Relative Volume Differs Between Platforms
Relative volume rarely agrees across platforms. One AAPL session computed five ways from the same bars shows why readings split most in the first hour.
Futures Tick Size and Tick Value Explained
Futures tick size is the smallest price step; tick value is what one step pays. CME specs for ES, MES, NQ, MNQ, CL, MCL, GC, MGC, ZN and ZB, plus the P&L math.
Xetra Trading Hours and Holidays 2026–2027
Xetra trading hours run 9:00 to 17:30 CET. Every 2026 and 2027 closure, the auction clock, the New York overlap, and why German stocks move until 22:00.
How to Backtest a Trading Strategy in Python
How to backtest a trading strategy in under 80 lines of plain Python: a 5/20 moving average crossover with next-open fills, fees, slippage and a split fix.
What Is Backtesting in Trading?
Backtesting replays a trading rule over past bars, seeing only what was known at the time. What comes out, four ways it lies, and when a result is too good.
Options Expiry Days in India: NSE and BSE
Which day do options expire in India? Nifty 50 weekly on Tuesday (NSE), Sensex on Thursday (BSE), everything else monthly, pinned to the SEBI circulars.
Can You Day Trade an Index Fund? ETFs vs Funds
Can you day trade an index fund? Index ETFs trade all session; index mutual funds price once at 4 p.m. ET and police round trips. Prospectus rules, quoted.
Short Selling Bans Explained: US, Germany, EU
Is short selling banned? Not in the US or Germany today, but it has been. Every real ban dated to its order, plus the two circuit breakers that still apply.
How to Read the US Equity Trade Tape
What each field on the US equity trade tape means, measured on 22 years of prints: timestamps, auction prints, condition codes, corrections and reused symbols.
US Stocks 23/5 Trading: The December 2026 Plan
US stocks are set to trade 23/5 from December 6, 2026 if the feeds are ready. What overnight trading does to trade dates, daily bars, volume and LULD bands.
What Replaced the PDT Rule? Intraday Margin
The PDT rule ended June 4, 2026. Here is the intraday margin standard that replaced it, what the $2,000 minimum means, and how a $5,000 account is treated.
How to Short a Stock, Step by Step
How to short a stock, step by step: margin approval, the Reg SHO locate, the short mark, borrow fees and buying to cover, with a 100-share worked example.
NDX vs QQQ Options: Which One to Trade?
NDX vs QQQ options compared on contract size, cash or share settlement, exercise style, AM or PM expiry and 60/40 tax, with same-day IV and volume data.
Can a Death Cross Be Bullish? The SPY Record
Can a death cross be bullish? Every SPY 50/200-day cross in our daily data, with 1, 3, 6 and 12 month forward returns and how often the index was higher.
Short Positions in German Stocks: Bundesanzeiger
How to find short positions in German stocks: search the Bundesanzeiger net short position register by issuer, and learn why the German Short-Quote is a floor.
What Happens After a Reverse Stock Split?
What happens after a reverse stock split: the changes holders see, the Nasdaq $1 minimum bid rule behind most of them, and how recent US names traded after.
Altria (MO) Dividend Increase History by Year
Altria (MO) dividend increase history by year: each raise's announcement date and size, the August cadence, the latest raise, and how cash flow covers it.
The 7% Sell Rule Explained: O'Neil's Stop-Loss
The 7% sell rule says sell any stock that falls 7 to 8% below your buy price. The recovery math behind the cap and why a stop order can fill well below 7%.
Fed Call vs House Call vs Exchange Call
Fed call vs house call vs exchange call: what trips each margin call and how long you get under Reg T and FINRA Rule 4210, with one worked example.
Single Stock Futures: CME's New Contracts
Single stock futures explained: CME's 2026 contracts, how the price embeds financing minus dividends, the 15% margin floor, and why 60/40 tax does not apply.
How an IPO's Opening Price Is Set
How an IPO's opening price is set on Nasdaq and the NYSE, from the display-only period to the launch call, and why the first print can land hours after 9:30.
Biggest Short Squeezes in History, Ranked
The biggest short squeezes in history, ranked on three yardsticks from peak price multiple to documented short seller losses: Volkswagen 2008 to nickel 2022.
What Is an Implied Volatility Index? IV30 & VIX
An implied volatility index is a constant 30-day IV built from two expirations. See the IV30 formula worked on real AAPL options, and how the VIX family fits.
Which Stocks Have Weekly Options? How to Tell
Most large caps and major ETFs have weekly options with Friday expirations. Most small caps are monthly only. How to tell from a chain, plus a live count.
How Long Can You Hold a Short Position?
How long can you hold a short position? A short sale has no expiry date. Four clocks end it: a recall and buy-in, Reg SHO close-outs, borrow fees, or margin.
Stop Orders on Options: What Actually Triggers
A stop order on an option rarely sits on an exchange. Your broker holds it and fires it off the last trade, the bid, or the mark. That choice decides the fill.
When Do Options Start Trading After an IPO?
Options do not list on IPO day. See how many sessions the biggest new listings waited for a first option print, and the exchange rules that gate it.
Implied Volatility vs Beta: What Each Tells You
Implied volatility vs beta: one is the option market's forward estimate of total movement, the other a backward slope against an index. Ten names, measured.
Futures Block Trades and CME Minimums
A futures block trade is privately negotiated away from the order book. How CME Rule 526 minimums work, and why your chart never showed the trade.
What Time Do Options Start Trading?
What time do options start trading? US listed options open at 9:30 a.m. ET. Here is the 7:30 a.m. order acceptance window and the overnight index session.
Option Expiration Cycles Explained
Option expiration cycles decide which months appear on a stock's option chain. See how the three cycle groups work and why LEAPS always land in January.
Apple Stock Split History and Ratios
Apple stock split history in full: every AAPL split with its ratio, its effective date, the price it followed, and the cumulative factor behind old quotes.
Monthly Dividend ETFs: Who Actually Pays
Monthly dividend ETFs pay 12 times a year. See which fund families actually do it, why the headline yield is not comparable, and when the cash lands.
How to Become a Registered Market Maker
How to become a market maker: exchange registration, two sided quoting size and width rules, net capital under Rule 15c3-1, and what suspension means.
Why stocks drop on the ex-dividend date
Why do stocks drop on the ex-dividend date? The drop is a mechanical price adjustment. See how far real payers actually opened below the prior close.
Street Name vs Holder of Record: Cede & Co
Street name vs holder of record: your broker holds the position at DTC and Cede & Co is the registered owner. What that means for dividends and proxies.
Who Sets the Ex-Dividend Date? Not the Board
Who sets the ex-dividend date? The listing exchange does, under FINRA uniform practice rules, working from the record date and the T+1 settlement cycle.
Who Are the Biggest Market Makers?
Who are the biggest market makers? The firms that quote US stocks and options, and how to read your own broker's Rule 606 report to see who fills your orders.
Due Bills and Stock Splits: Ex-Date Timing
Why a stock split's ex-date lands after the payable date, what a due bill is, who tracks it, and the full timeline from record date to first adjusted session.
Qualified Dividend Holding Period: 61 Days
The qualified dividend holding period is more than 60 days inside a 121-day window around the ex-dividend date. See the exact count, with worked dates.
When Did the US Stock Market Start? 1792
The US stock market started with the 1792 Buttonwood Agreement, signed by 24 brokers. Every date that follows, and how a call auction became 9:30 to 4:00.
Stop Order vs Stop-Limit Order: How Each Fills
A stop order becomes a market order and fills at any price. A stop-limit becomes a limit order and can miss the exit entirely. Five years of gap data show it.
FINRA Margin Debt Statistics, Explained
FINRA margin debt statistics explained: the rule behind the filing, the third week release, the four to seven week lag, and how to read the history since 1997.
Payment in Lieu of Dividends, Explained
A payment in lieu of dividends arrives when your broker lends your shares out. Here is the full mechanic, and why the tax character differs from a dividend.
Options Expiration Calendar 2026: All 12 Dates
The full 2026 options expiration calendar: twelve monthly third Fridays, the four quarterly dates, and the holiday rule that can shift one to a Thursday.
When Are 13F Filings Due? 2026 Deadlines
13F filings are due 45 days after each quarter ends. The four 2026 deadlines, the rolls that move them, and what the form never shows you about a portfolio.
What H1 and H2 Mean in Company Reporting
H1 and H2 are the two halves of a reporting year. What the labels mean, how to read FY26 Q3, and why H1 2026 covers different calendar months by issuer.
Why Stock Quotes Are Delayed 15 Minutes
Why are stock quotes delayed 15 minutes? How exchange data licensing sets the rule, and what a quarter hour of staleness actually costs on real prices.
How to Calculate Covered Call Returns
How to calculate covered call returns: net debit, break even, static return and return if called, worked through one contract, plus the annualized catch.
What Is the High-Low Index? Market Breadth
The High-Low Index is the 10-day average of Record High Percent. See the formula worked in round numbers, plus the sample size trap on a quiet tape.
When Is the COT Report Released?
The CFTC releases the COT report every Friday at 3:30 pm ET, measured as of Tuesday's close. See the schedule, the three-day lag, and how to read it.
US Market Hours and Daylight Saving Time
US market hours never change in New York: 9:30 to 16:00 ET all year. See what daylight saving does to the open in London, Frankfurt, Tokyo and Sydney.
What Happens If an Option Expires In the Money
If an option expires in the money by at least $0.01, the OCC exercises it automatically. See what the long and short sides owe, and what pin risk costs.
How to Find a Stock's Earnings Date
A company sets its own earnings date and confirms it in a press release and an 8-K filing. Here is where to look, and how far an estimated date can move.
Price Return vs Total Return: The Real Gap
Price return vs total return: the S&P 500 headline index leaves out dividends. See the compounding gap measured over 20 years and where each version is used.
How to Find a Lockup Expiration Date
A lockup expiration date lives in the IPO prospectus, not on a calendar page. Where to find it, and why counting 180 days from the first trade gets it wrong.
Nikkei 225 Options and SQ Settlement
Nikkei 225 options settle in cash against the SQ, an opening print from all 225 stocks. How the second Friday settlement works and what long premium costs.
Trailing vs Forward Dividend Yield Explained
Trailing dividend yield counts the last twelve months of payouts; forward yield annualizes the latest declared one. See why two screeners can disagree.
Mutual Funds vs ETFs: What Actually Differs
Mutual funds vs ETFs: one price a day at NAV against a live market price. See what really differs in pricing, spreads, capital gains, and share classes.
When Do Mutual Fund Trades Settle?
Mutual fund settlement runs on a different clock than fund pricing. Walk a sale through both clocks, day by day, and see when the cash is really yours.
What Is Max Pain in Options? The Real Math
Max pain is the strike where option holders collect the least at expiry. See the calculation on a real SPY chain and how close settlement actually landed.
Covered Call vs Cash-Secured Put
A covered call and a cash-secured put at one strike share a payoff shape. See both priced on the same SPY chain, and where the two really differ.
US Stock Market Hours Around the World
US stock market hours run 9:30 a.m. to 4:00 p.m. New York time. See that session converted into major world time zones, plus the twice yearly clock shifts.
American vs European Options Explained
American options can be exercised on any trading day, European options only at expiration. How SPY and SPX differ, and when early exercise matters.
Free Stock Market Data API, No Key Required
A free stock market data API with no key and no signup: seven curated JSON queries over US equities and options, cached at the edge and open to AI agents.
Free SQL API for Stock Market Data
A free SQL API for stock market data: write real SQL against 22 years of US equities, dividends, and fundamentals. 100 queries a day, no credit card.
What Is IV Crush? Measured on Real Earnings
IV crush is the overnight collapse of option implied volatility after an event. We scanned six weeks of the US options tape and measured every big one.
Which Stocks Have Daily Options?
SPY, QQQ and IWM list a new options expiration every trading day, and the index roots go deeper. See which tickers carry dailies and which only get Fridays.
When Is Short Interest Released?
FINRA publishes short interest twice a month, mid-month and month-end, about two weeks after each settlement date. See the live release cadence and lag.
How Often Do Stocks Split?
How often do stocks split? A data study since 2016: reverse splits far outnumber the forward ones that grab headlines, hundreds of each every year.
Triple Witching 2026 Dates and Volume Data
Triple witching 2026 falls on March 20, June 18, September 18 and December 18. See how market-wide dollar volume moved on the last witching session.
Highest Days to Cover Stocks Right Now
The stocks with the highest days to cover from the latest FINRA short interest settlement, and why the raw top of the list is a liquidity artifact.
How Ex-Dividend Dates Affect Options
How ex-dividend dates affect options: why ordinary dividends don't move strikes, when to exercise a call early, and how a liquid option's greeks glide through.
Does a Stock Go Up After a Split?
Does a stock go up after a stock split? A data study of forward splits since 2016: the run-up comes before, and the median stock trailed the market afterward.
What Is a Special Dividend? (With Examples)
A special dividend is a one-time payout outside a company's regular schedule. Why Costco and National Beverage pay them, and what they mean for options.
How Leveraged ETFs Work (and Why They Decay)
How 3x leveraged ETFs like SOXL actually work, why they can beat or lag their multiple over time, and why inverse funds such as SOXS keep reverse-splitting.
The Option Greeks Explained: Delta to Rho
Delta, gamma, theta, vega and rho, the five option greeks, demonstrated by tracing one real SPY call through its whole life against the stock.
What Is Option Vega? Volatility Sensitivity
Vega measures an option's sensitivity to implied volatility. Watch IV spike on a real SPY call, see vega grow with time, and drive the earnings vol crush.
What Is Implied Volatility? IV, Explained
Implied volatility is the future move an option's price implies. See IV across stocks, the term structure, the volatility skew, and a year of SPY's vol regime.
What Is Option Theta? Time Decay Explained
Theta measures an option's daily time decay. Watch it deepen on a real SPY call into expiry, see decay accelerate, and why it's the seller's income.
What Is Option Gamma? Delta's Accelerator
Gamma measures how fast an option's delta changes. See the at-the-money bell, why it spikes near expiry, and how it powers 0DTE and the gamma squeeze.
What Is Option Delta? A Plain-English Guide
Option delta measures how much an option moves per $1 in the stock. Watch it track a real SPY call across the strike and see the moneyness S-curve.
Most Shorted Stocks Right Now, Measured
The most shorted stocks by days to cover and by shares short, from the latest exchange-reported settlement. Liquid names only, refreshed as new prints land.
Unusual Volume Stocks This Week, Measured
Unusual volume stocks this week, ranked: trailing-week turnover vs. each name's prior 40 sessions, with weekly returns, rarity context and persistence.
Is the Stock Market Open Today?
Is the US stock market open today? A computed open/closed status, today's calendar, every upcoming holiday, and what happens to orders placed while it's closed.
When Do Mutual Funds Trade? NAV Pricing at 4 pm
Mutual funds trade once a day, priced at the 4 pm ET NAV, no intraday prices, no limit orders. See when orders fill, the broker cutoff, and T+1 settlement.
When Do 0DTE Options Trade? By the Hour
0DTE options trade heaviest in the morning, not at the close: hourly volume, the calls-vs-puts clock, weekday shares and same-day spreads, all measured.
What Is Average Daily Volume (ADV)?
Average daily volume is a stock's typical shares traded per day. It is the denominator inside days to cover, relative volume, and every liquidity screen.
IPO Lockup Expiration: Meaning & Release Date
A lockup expiry is the day IPO insiders can finally sell, customarily 180 days after listing. Where to find the exact end date, and how five unlocks traded.
FINRA Short Interest Data, Explained
Where short interest data actually comes from: FINRA's twice-monthly settlement file and its daily short volume file. Schedules, contents, and failure modes.
Upcoming Ex-Dividend Dates: Stocks This Week
See which stocks have upcoming ex-dividend dates this week and next: the biggest names, per-share payouts and pay dates, plus what the ex-day price drop does.
What Is Dividend Yield? What's Normal in 2026
Dividend yield is annual dividends per share divided by price. See the median payer's yield, what's normal by sector, and when a high yield is a trap.
What Is Triple Witching? Volume & Volatility
Triple witching is the quarterly session when index futures, index options and stock options expire together. Volume and volatility, measured on the real tape.
What Is a Short Squeeze? GameStop, Measured
A short squeeze is a rally that feeds on short sellers buying to close. GameStop's 2021 records, short interest, days to cover and price, tell it in numbers.
What Is the Put-Call Ratio? A Data Guide
The put-call ratio is puts traded divided by calls traded. See its real range on the full US options tape: by expiration, index vs equity, and against a decade.
DTE Meaning in Options: Days to Expiration
DTE stands for days to expiration: calendar days, not trading days, until an option expires, and expiry day counts as zero. How to count it on a real chain.
When Do Options Expire? Friday 4 PM ET & Daily
Most options stop trading at the 4:00 PM ET close on expiration Friday; weeklies expire Fridays, monthlies the third Friday, and SPY and QQQ expire daily.
Why Do Stocks Gap Up or Down Overnight?
A gap up or gap down is the distance from the prior close to the 9:30 open, after 17.5 closed hours. SPY overnight gap size, Mondays widest, plus stop risk.
What Is Days to Cover? Short Interest Ratio
Days to cover, the short interest ratio, is shares short divided by daily volume: how many days the exit would take. Real settlement data shows what is high.
What Is a Stock Split? Ratios and Mechanics
A stock split multiplies share count and divides price, value unchanged. Real split records show which ratios companies pick, and what prices did next.
Market Order vs Limit Order, Measured
A market order fills now at the best available price; a limit order caps your price but may not fill. Real quote data shows what each choice costs in dollars.
How Monthly Stock Returns Are Measured
A monthly stock return depends on which two prices you pick, whether dividends count, and whether the series is split-adjusted. Each one measured on real data.
How Much Does It Cost to Trade Options?
Options commissions may be zero, but the bid-ask spread is real. See the median cost to trade SPY, QQQ, IWM, GLD, and TSLA options, in basis points.
What Is the NBBO? National Best Bid and Offer
The NBBO is the national best bid and offer, the one consolidated stock quote your broker must match or beat. See how fast it updates, from real tick data.
Why Are Spreads Wider at the Open? Real Data
Why are spreads wider at the open? Tick-level quotes price the opening premium half hour by half hour, show how fast it fades, and what premarket really costs.
What It Costs to Trade a Stock, Measured
Commissions are zero, but every stock trade pays the bid-ask spread. See the real cost of trading stocks, measured in basis points across 12 household names.
What Is FINRA Short Interest? Days to Cover
FINRA short interest is shares sold short and not yet bought back. See how it's reported twice monthly, settlement dates, days to cover and percent of float.
What Is a Reverse Stock Split? Good or Bad?
A 1-for-10 reverse stock split turns 10 shares into 1 at ten times the price, position value unchanged. Neutral arithmetic; the companies that use it are not.
Stock Market Hours: Open 9:30, Close 4:00 ET
What time does the stock market open and close? NYSE and Nasdaq regular hours run 9:30 a.m.–4 p.m. ET, plus premarket and after-hours; closed weekends.
Ex-Dividend Date vs. Record Date: Same Day?
Is the ex-dividend date the same as the record date? Since the T+1 switch in May 2024, yes, they fall on the same day for nearly every US dividend, measured.
Locked and Crossed Markets, Explained With Data
A locked market quotes the bid equal to the ask; a crossed market quotes the bid above it. See why Reg NMS bans both and how often each hits the tape.
How Big Is the OPRA Options Quote Feed?
How big is the options quote feed? We count one full day of OPRA-scale NBBO updates in our warehouse and measure it against the entire stock quote tape.
Options Volume vs. Open Interest, Explained
Volume counts contracts traded today; open interest counts contracts still outstanding. Both defined, plus one full day of the US options tape, measured.
What Is 0DTE? Zero Days to Expiry Options
0DTE options expire the same day they trade, zero days to expiry. What DTE means, how traders build a 0DTE trade, and one real contract traced to the bell.
What Is the Opening Auction? How Stocks Open
What the opening auction is, how one 9:30 a.m. cross sets each stock's official opening price, and why the open can differ from the first trade of the day.
What Is Dark Pool Trading? FINRA Volume Data
Dark pool trading matches stock orders with no displayed quotes. Every fill prints to the FINRA tape, the measured off-exchange share of five liquid stocks.
Stock Float vs. Shares Outstanding Explained
A stock's float is the shares free to trade, shares outstanding minus locked-up insider stock. See what counts as a low float and how thin floats trade.
What Is a Block Trade? Big Prints & the Data
What a block trade is, where the 10,000-share / $200,000 rule comes from, and how big prints reach the tape, dark pools, exchanges, on real block-trade data.
What Is RVOL (Relative Volume)? How to Read It
RVOL (relative volume) is a stock's volume ÷ its 20-day average: above 1 is busier-than-usual trading. Plus intraday time-of-day RVOL and what counts as high.
The Most Common SEC Filings, Explained by Data
The most common SEC filing is not the 10-K or the 10-Q. It is the insider Form 4. A data-backed guide to EDGAR's busiest forms, ranked, defined and explained.
Premarket and After-Hours Trading Hours (ET)
Premarket runs 4-9:30 a.m. ET, after-hours 4-8 p.m. See what the tape shows: each session's volume share, how much wider spreads cost, and when news moves.
What Is VWAP? Volume-Weighted Average Price
VWAP stands for volume-weighted average price. Definition: price times volume divided by total volume, reset daily. What it means on a real trading day.
What Is the Closing Auction? (Closing Cross)
What the closing auction is, why one 4 p.m. print sets the official close, and how market-on-close orders feed the day's biggest trade, on real tape data.
Stock Market Holidays 2026–2027: NYSE & Nasdaq
When is the stock market closed? Every upcoming NYSE & Nasdaq holiday and 1:00 p.m. early close for 2026–2027, from the live exchange calendar.
Why Short Interest Data Is Always Two Weeks Old
Short interest is measured twice a month and published on a lag. The FINRA cycle, the measured delay, what moves while a print is pending, and days to cover.
What Is a Bid-Ask Spread? Real Costs
Learn what a bid-ask spread is, how to calculate it, and what it costs per trade, with real spreads measured from tick-level quote data on US stocks.
How Do Market Makers Make Money? The Spread
What market makers do and how they earn the bid-ask spread, with real tick data: measured spreads, quote updates per second, and the SQL behind every number.
What Is the 2s10s Spread? Yield Curve Data
What the 2s10s spread is, how the Treasury yield curve works, and what past inversions looked like, with every chart built from auditable market data.
Short Interest vs Short Volume: The Difference
Short interest and daily short volume measure different things. See real per-ticker numbers, days-to-cover math, and the exact query behind every figure.
What Is an Ex-Dividend Date? How It Works
The ex-dividend date decides who gets paid: buy before it and the dividend is yours, buy on it and it isn't. See the four key dates on real US timelines.