One Clearinghouse, Many Options Exchanges

US listed options trade across more than a dozen options exchanges, and every contract on all of them clears in one place. The Options Clearing Corporation issues and guarantees the contract itself, which leaves the exchange that lists a strike acting as a matching engine rather than as the maker of the instrument. A call bought on one exchange this morning can be sold on a different exchange tomorrow, through a different broker, with no reference back to where the position opened.

An option is a contract carrying the right to buy or sell 100 shares at a fixed strike price until a fixed expiration date. That is the only definition this page needs. The structure built around it is where the mechanics live.

How many options exchanges are there?

The count is not a constant worth memorizing. Venues launch and get folded into their parents' operating groups, and the official participant registry is the only honest source for the current number. As of October 2026 that registry lists 20 US options exchanges. The panel below reads it live every time this page is rebuilt, and the figure ages with the market rather than with the author.

SELECT
    any(name)          AS exchange,
    any(acronym)       AS code,
    mic                AS mic,
    any(operating_mic) AS operating_group
FROM global_markets.stocks_exchanges
WHERE asset_class = 'options'
  AND type = 'exchange'
GROUP BY mic
ORDER BY operating_group, exchange

Read the operating group column and the shape of the industry appears. The 20 venues resolve to a much smaller set of corporate parents, and several of those parents run three or four separate exchanges side by side. Running multiple venues under one roof is a pricing strategy: each exchange carries its own fee schedule and its own rule for deciding who gets filled.

One issuer, many matching engines

In equities, the thing you trade exists apart from any exchange. The company issued the shares, and the exchange is a place to meet. A listed option works differently. The contract comes into existence at the clearinghouse when a buyer and a seller open a position against each other, and from that moment the clearinghouse stands on both sides of it. Your broker faces the clearinghouse. So does the market maker who sold you the call.

Two consequences are visible from a retail account. Open interest is a single pooled figure per contract rather than a tally kept per exchange, which is part of why it updates overnight instead of continuously; the gap between that figure and daily volume is covered in options volume versus open interest. And a sell to close order can route to whichever venue shows the best price, with no requirement to return to the exchange where the position was opened.

This is also why an exchange outage is an inconvenience rather than a trap. The position sits at the clearinghouse, and the other venues keep quoting the same contract.

Why the options quote feed is the largest in US markets

Start with how many separate instruments a single stock generates. Every expiration date carries a ladder of strikes, and every strike carries a call and a put.

SELECT
    underlying_symbol                      AS underlying,
    count()                                AS listed_contracts,
    countIf(volume > 0)                    AS contracts_traded,
    formatDateTime(any(date), '%b %e, %Y') AS as_of_label
FROM global_markets.options_greeks
WHERE underlying_symbol IN ('AAPL', 'MSFT', 'NVDA', 'SPY', 'KO')
  AND date = (
      SELECT max(date)
      FROM global_markets.options_greeks
      WHERE underlying_symbol = 'AAPL'
        AND date <= '2026-09-30'
  )
GROUP BY underlying
ORDER BY listed_contracts DESC

On Sep 30, 2026, SPY carried 5133 separate contracts in the daily greeks file, 5133 of them with recorded volume. Now multiply. Each of those contracts can be quoted on each of the 20 exchanges, each quote carries a bid and an ask with sizes attached, and every one of them is entitled to update whenever the underlying ticks a penny.

Those quotes consolidate into a single feed, the Options Price Reporting Authority, usually written OPRA. OPRA collects quotes and trades from every participating options exchange and publishes them as one stream, the same arrangement equities use with their consolidated tape. The difference is the instrument count above, and it is why OPRA routinely runs the highest message rate of any US market data feed. The engineering of that firehose is its own subject, measured in how big the options quote feed is.

Who decides which options exchange fills your order?

A retail order almost never names a venue. The broker's routing system picks, and the exchanges compete for that routing decision in two currencies: the allocation rule and the fee schedule.

WITH venue_volume AS
(
    SELECT
        toString(exchange) AS exchange_id,
        sum(size)          AS contracts
    FROM global_markets.options_trades
    WHERE underlying_symbol = 'AAPL'
      AND sip_timestamp >= toDateTime('2026-09-15 00:00:00')
      AND sip_timestamp <  toDateTime('2026-09-16 00:00:00')
    GROUP BY exchange_id
),
venue_names AS
(
    SELECT
        toString(id) AS exchange_id,
        any(acronym) AS code,
        any(name)    AS full_name
    FROM global_markets.stocks_exchanges
    WHERE asset_class = 'options'
    GROUP BY exchange_id
)
SELECT
    coalesce(nullIf(n.code, ''), nullIf(n.full_name, ''), concat('ID ', v.exchange_id)) AS venue,
    round(toFloat64(v.contracts) / 1000, 1)                                             AS contracts_thousands,
    round(100 * toFloat64(v.contracts) / sum(toFloat64(v.contracts)) OVER (), 1)        AS share_pct
FROM venue_volume AS v
LEFT JOIN venue_names AS n USING (exchange_id)
ORDER BY share_pct DESC

Across that pinned session, AAPL option volume spread over 18 venues. The largest took 12.9% of contracts traded and the smallest on the list took 0.7%. No single exchange owns the name.

Allocation is the rule that splits a fill among the firms quoting the same best price. Common models include pro rata by displayed size, priority to whoever posted at that price first, a customer priority overlay that fills public customer orders ahead of professional accounts, and a guaranteed participation for the exchange's designated market maker. The largest options market makers build their quoting around these rules, since the rule decides how much of the flow a given quote actually earns.

Many exchanges also run a price improvement auction. A broker submits the order with a starting price, the exchange exposes it for a brief interval measured in milliseconds, and other participants can better that price before the order fills. Most of the order's visible life happens inside that window.

The fee schedule is the second currency. Under a maker taker schedule the exchange pays a rebate to the resting quote that gets hit and charges a fee to the order that takes it; several options exchanges invert the signs. A retail order that never chose a venue still sits inside those economics, and maker taker fees and rebates walks through who collects what.

Why are options spreads wider than the underlying stock?

Take a baseline first. The panel below samples one midday hour of quotes on September 15, 2026 across five household names and reports the median quoted spread.

SELECT
    ticker AS ticker,
    round(quantileDeterministic(0.5)(
        toFloat64(ask_price - bid_price),
        toUInt64(sequence_number)) * 100, 2)                       AS spread_cents,
    round(quantileDeterministic(0.5)(
        20000 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price),
        toUInt64(sequence_number)), 2)                             AS spread_bps
FROM global_markets.cache_stocks_quotes
WHERE ticker IN ('AAPL', 'MSFT', 'NVDA', 'SPY', 'KO')
  AND sip_timestamp >= toDateTime('2026-09-15 15:00:00')
  AND sip_timestamp <  toDateTime('2026-09-15 16:00:00')
  AND bid_price > 0
  AND ask_price > bid_price
GROUP BY ticker
ORDER BY spread_bps DESC

The tightest of the five, SPY, held a median quoted spread of 0.26 basis points. A basis point is one hundredth of a percent, which places that round trip cost at well under a tenth of a percent. The widest, MSFT, quoted 2 basis points.

Options on those same names quote wider, and the source of the width is mechanical rather than competitive. A firm that sells you a call takes on a position whose value moves with four separate things: the stock price, the passage of time, the market's estimate of future volatility, and to a small degree interest rates. It can hedge the first with shares. The rest it carries.

SELECT
    multiIf(days_to_expiry <= 7,  '0 to 7 days',
            days_to_expiry <= 21, '8 to 21 days',
            days_to_expiry <= 45, '22 to 45 days',
            days_to_expiry <= 90, '46 to 90 days',
                                  '91 or more days') AS dte_bucket,
    round(100 * avg(implied_volatility), 1)          AS iv_pct,
    round(avg(vega), 3)                              AS avg_vega
FROM global_markets.options_greeks
WHERE underlying_symbol = 'AAPL'
  AND date = (
      SELECT max(date)
      FROM global_markets.options_greeks
      WHERE underlying_symbol = 'AAPL'
        AND date <= '2026-09-30'
  )
  AND iv_converged = 1
  AND volume > 0
  AND abs(toFloat64(strike_price) / toFloat64(underlying_close) - 1) < 0.05
GROUP BY dte_bucket
HAVING count() >= 5
ORDER BY min(days_to_expiry)

Implied volatility is the volatility figure that makes an option pricing model agree with the option's market price, quoted as an annualized percent. Vega is the sensitivity to it: the change in an option's price for a one point move in implied volatility. Near the money AAPL contracts in the 0 to 7 days bucket averaged 27.7% implied volatility with 0.107 of vega, while the 91 or more days bucket averaged 27.7% with 1.208. Vega grows with time to expiry, and shares carry no vega at all, which leaves that exposure unhedged by any quantity of stock.

Add the division problem from the feed section. A stock concentrates all of its volume into one line. The same company's option volume splits across thousands of contracts, and each individual line sees a fraction of the attention. Competition among 20 exchanges narrows the quote around that carried risk. It does not remove the risk.

FAQ

Do all US listed options clear at the same clearinghouse?

Yes. Every listed US equity and index option clears at the Options Clearing Corporation, which issues the contract and becomes the counterparty to both the buyer and the seller. The exchange where the trade matched does not hold the position afterward.

Can I close an option on a different exchange than I bought it on?

Yes. Listed contracts are fungible across venues, and a closing order routes to whichever exchange shows the best price at that moment. Your broker handles the routing, and the resulting fill reduces the same pooled open interest.

How many options exchanges are there in the US?

The participant registry read on this page listed 20 as of October 2026. The figure moves as venues launch or are folded into a parent operating group, which is why this page counts the live list rather than quoting a fixed number.

What is OPRA?

The Options Price Reporting Authority is the consolidated feed that collects quotes and trades from every participating US options exchange and distributes them as one stream. It carries the highest message rates in US market data.

Why are option bid ask spreads wider than the stock's?

The firm quoting an option carries exposure to time and to implied volatility that shares cannot hedge, and each underlying's volume is split across thousands of separate contracts. Both widen the quote relative to the single, heavily traded line of the underlying stock.

Every panel on this page ships with the SQL that produced it, one expander away. To measure venue share for a different underlying, or line up a contract's open interest against its volume, ask the question in plain English on the Strasmore terminal.