What one 100 share contract covers after a non whole split ratio, 2020 to July 2026
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 2026-08-04, from How Stock Splits Affect Your Options.
| ratio_label | direction | split_count | shares_per_contract_after |
|---|---|---|---|
| 3-for-2 | forward split | 33 | 150 |
| 6-for-5 | forward split | 9 | 120 |
| 11-for-10 | forward split | 39 | 110 |
| 21-for-20 | forward split | 10 | 105 |
| 26-for-25 | forward split | 10 | 104 |
| 1-for-4 | reverse split | 259 | 25 |
| 1-for-5 | reverse split | 401 | 20 |
| 1-for-10 | reverse split | 1139 | 10 |
| 1-for-15 | reverse split | 216 | 6.67 |
| 1-for-20 | reverse split | 489 | 5 |
- Rows × columns
- 10 × 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 |
|---|---|---|---|
ratio_label |
text | 10 distinct values (1-for-10, 1-for-15, 1-for-20…) | |
direction |
text | 2 distinct values (forward split, reverse split) | |
split_count |
number | 9 to 1,139 | count |
shares_per_contract_after |
number | 5 to 150 | count |
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.
Run it yourself
This is the exact query behind the result above. Change a ticker, a date or a column and run it against the warehouse — no account, no key. The no-signup tier is smaller than the one this page was computed on; a query that reaches past it comes back saying which plan runs it.
WITH ratio_counts AS (
SELECT concat(toString(toUInt32(split_to)), '-for-', toString(toUInt32(split_from))) AS ratio_label,
if(toFloat64(split_to) > toFloat64(split_from), 'forward split', 'reverse split') AS direction,
round(100 * toFloat64(split_to) / toFloat64(split_from), 2) AS shares_per_contract_after,
count() AS split_count
FROM global_markets.stocks_splits
WHERE execution_date >= toDate('2020-01-01')
AND execution_date < toDate('2026-08-01')
AND toFloat64(split_from) > 0
AND toFloat64(split_to) > 0
AND toFloat64(split_from) = round(toFloat64(split_from))
AND toFloat64(split_to) = round(toFloat64(split_to))
AND modulo(toUInt32(split_to), toUInt32(split_from)) != 0
GROUP BY ratio_label, direction, shares_per_contract_after
),
ranked AS (
SELECT ratio_label,
direction,
shares_per_contract_after,
split_count,
row_number() OVER (PARTITION BY direction ORDER BY split_count DESC) AS rank_in_direction
FROM ratio_counts
)
SELECT ratio_label,
direction,
split_count,
shares_per_contract_after
FROM ranked
WHERE rank_in_direction <= 5
ORDER BY shares_per_contract_after DESC