Average quoted spread and time on the penny floor, pinned session
Answered against 22 years of US equities and 12 years of US options data and published with the query that produced it. This result is stored as of 2026-08-13, from Half-Penny Tick Sizes Under Rule 612.
| symbol | avg_quoted_spread_cents | time_at_penny_floor_pct |
|---|---|---|
| F | 1 | 99.8 |
| PFE | 1.02 | 99.1 |
| NVDA | 1.19 | 81.6 |
| SPY | 1.25 | 77.7 |
| KO | 1.35 | 71.5 |
| AAPL | 1.5 | 68.9 |
| MSFT | 9.19 | 5.1 |
| GS | 69.55 | 0.3 |
- Rows × columns
- 8 × 3
- Computed
- Completeness
- No missing values
- Source
- US exchange, SIP and OPRA market data
- Licence
- Strasmore terms · free, no signup
What each column holds
| Column | Type | Range | Notes |
|---|---|---|---|
symbol |
text | 8 distinct values (AAPL, F, GS…) | |
avg_quoted_spread_cents |
number | 1 to 69.55 | |
time_at_penny_floor_pct |
number | 0.3 to 99.8 | percent |
Computed from Strasmore's warehouse of US exchange, SIP and OPRA market data. Equity prices are delayed; options greeks and implied volatility are end-of-day. This result is stored, not recomputed on load — it is exactly the numbers that were returned on , and the query below is what returned them.
the exact SQL behind every number
WITH per_second AS
(
SELECT
ticker,
toDateTime(sip_timestamp) AS quote_second,
max(toFloat64(bid_price)) AS best_bid,
min(toFloat64(ask_price)) AS best_ask
FROM global_markets.cache_stocks_quotes
WHERE ticker IN ('AAPL', 'MSFT', 'NVDA', 'SPY', 'KO', 'PFE', 'F', 'GS')
AND sip_timestamp >= '2026-08-05 13:30:00'
AND sip_timestamp < '2026-08-05 20:00:00'
AND bid_price > 0
AND ask_price > 0
GROUP BY ticker, quote_second
)
SELECT
ticker AS symbol,
round(avg(best_ask - best_bid) * 100, 2) AS avg_quoted_spread_cents,
round(100 * countIf(best_ask - best_bid < 0.011) / count(), 1) AS time_at_penny_floor_pct
FROM per_second
WHERE best_ask > best_bid
GROUP BY ticker
ORDER BY avg_quoted_spread_cents ASC
Run your own version of this
The same 22 years of US equities and 12 years of options data are queryable in SQL or plain English. A free account runs 100 queries a day and takes no card.
More from this analysisHalf-Penny Tick Sizes Under Rule 612
What one cent is worth, as a share of the closing price
ranking 8×3
→
Share of the session spent at each quoted spread, three names
ranking 5×4
→
Share of each 15 minute bucket spent at a one cent quoted spread
series 30×3
→
What one cent is worth, by share price band
ranking 8×3
→
Share of prints that landed on a sub-penny price
ranking 7×3
→
AAPL sub-penny print rate by trade size, 17 June 2026
ranking 5×3
→
See all 2,170 queries →