STRASMORE/EXPLORE 3,256 QUERIES

The hindsight ceiling: SPY buy and hold, the same year without its biggest up days, and perfect one-day foresight

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 2026-07-31, from Look-Ahead Bias: The Backtest Killer.

as of table 10×5read in context →
The hindsight ceiling: SPY buy and hold, the same year without its biggest up days, and perfect one-day foresight — 10 rows by 5 columns, computed from US exchange, SIP and OPRA data.
yearsessionsbuy_and_hold_pctwithout_big_up_days_pcthindsight_ceiling_multiple
20162529.6-1.84.3
201725119.419.42.2
2018251-6.3-18.76.4
201925228.8224.2
202025316.2-44.927.7
20212522721.54.9
2022251-19.5-56.219.8
202325024.321.55.1
202425223.315.24.4
202525016.4-6.66.3
Rows × columns
10 × 5
Computed
Completeness
No missing values
Source
US exchange, SIP and OPRA market data
Licence
Strasmore terms · free, no signup
Formats
JSON · CSV · the SQL below

What each column holds

Column definitions for The hindsight ceiling: SPY buy and hold, the same year without its biggest up days, and perfect one-day foresight, derived from the stored result.
ColumnTypeRangeNotes
year number 2,016 to 2,025
sessions number 250 to 253
buy_and_hold_pct number -19.5 to 28.8 percent
without_big_up_days_pct number -56.2 to 22 percent
hindsight_ceiling_multiple number 2.2 to 27.7

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 bars AS (
    SELECT date,
           toFloat64(close) AS c,
           any(toFloat64(close)) OVER (ORDER BY date ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING) AS prev_c
    FROM global_markets.stocks_daily_aggs
    WHERE ticker = 'SPY'
      AND date >= toDate('2015-12-01')
      AND date <= toDate('2025-12-31')
),
rets AS (
    SELECT toYear(date) AS year,
           c / prev_c - 1 AS r
    FROM bars
    WHERE date >= toDate('2016-01-01')
      AND prev_c > 0
)
SELECT year,
       count() AS sessions,
       round(100 * (exp(sum(log(1 + r))) - 1), 1) AS buy_and_hold_pct,
       round(100 * (exp(sumIf(log(1 + r), r < 0.02)) - 1), 1) AS without_big_up_days_pct,
       round(exp(sum(log(1 + abs(r)))), 1) AS hindsight_ceiling_multiple
FROM rets
GROUP BY year
ORDER BY year
⌘/Ctrl + Enter

Work with this data in your AI assistant

Opens ready to query, with this page's data. Free, no account.

More from this analysisLook-Ahead Bias: The Backtest Killer
Survivorship in the universe: names trading each year, share still listed in July 2026, and median return table 10×6 → Same-bar decision vs a one-session lag: SPY, average session gain, 2016-2025 table 10×5 → One rule, two fill conventions: SPY equity curves through 2024 series 12×4 → Median shares per executed print, 2024 ranking 5×2 → Distance from the signal close to the next session's open, 2024 ranking 5×3 → How far SPY travels after the minute your signal fired (June 2024) ranking 5×3 → See all 3,256 queries →