Share of the session spent at each quoted spread, three names
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.
| quoted_spread | aapl_pct | f_pct | gs_pct |
|---|---|---|---|
| 1 cent | 68.9 | 99.8 | 0.3 |
| 2 cents | 19 | 0.2 | 0.2 |
| 3 cents | 7.8 | 0 | 0.2 |
| 4 cents | 3.1 | 0 | 0.3 |
| 5 cents or wider | 1.2 | 0 | 98.9 |
- Rows × columns
- 5 × 4
- 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 |
|---|---|---|---|
quoted_spread |
text | 5 distinct values (1 cent, 2 cents, 3 cents…) | |
aapl_pct |
number | 1.2 to 68.9 | percent |
f_pct |
number | 0 to 99.8 | percent |
gs_pct |
number | 0.2 to 98.9 | 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', '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
),
graded AS
(
SELECT
ticker,
least(toUInt16(round((best_ask - best_bid) * 100)), 5) AS spread_cents
FROM per_second
WHERE best_ask > best_bid
),
totals AS
(
SELECT
ticker,
count() AS quoted_seconds
FROM graded
GROUP BY ticker
),
shares AS
(
SELECT
g.ticker AS ticker,
g.spread_cents AS spread_cents,
count() / any(t.quoted_seconds) AS time_share
FROM graded AS g
INNER JOIN totals AS t ON t.ticker = g.ticker
GROUP BY g.ticker, g.spread_cents
)
SELECT
if(spread_cents >= 5,
'5 cents or wider',
concat(toString(spread_cents), if(spread_cents = 1, ' cent', ' cents'))) AS quoted_spread,
round(100 * sumIf(time_share, ticker = 'AAPL'), 1) AS aapl_pct,
round(100 * sumIf(time_share, ticker = 'F'), 1) AS f_pct,
round(100 * sumIf(time_share, ticker = 'GS'), 1) AS gs_pct
FROM shares
GROUP BY spread_cents
ORDER BY spread_cents ASC
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