Same rule, prior-session signal against same-session signal, SPY by year
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 2026-08-06, from Reproducible Backtest in Python, No API Key.
| year | next_bar_pct | same_bar_pct | gap_pp |
|---|---|---|---|
| 2017 | 16 | 17.1 | 1.1 |
| 2018 | 6.1 | 2.1 | 3.9 |
| 2019 | 7.6 | 8.5 | 1 |
| 2020 | 17.4 | 18.5 | 1.1 |
| 2021 | 18.7 | 20.4 | 1.7 |
| 2022 | -24.7 | -22.4 | 2.3 |
| 2023 | 9.4 | 6.6 | 2.8 |
| 2024 | 13 | 10.8 | 2.2 |
| 2025 | 10.4 | 8.7 | 1.6 |
- Rows × columns
- 9 × 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 |
|---|---|---|---|
year |
number | 2,017 to 2,025 | |
next_bar_pct |
number | -24.7 to 18.7 | percent |
same_bar_pct |
number | -22.4 to 20.4 | percent |
gap_pp |
number | 1 to 3.9 |
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 daily AS
(
SELECT
toDate(toTimeZone(window_start, 'America/New_York')) AS d,
toFloat64(argMax(close, window_start)) AS px
FROM global_markets.delayed_stocks_minute_aggs
WHERE ticker = 'SPY'
AND window_start >= '2016-01-01 00:00:00'
AND window_start < '2026-01-01 05:00:00'
AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
+ toMinute(toTimeZone(window_start, 'America/New_York'))) >= 570
AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
+ toMinute(toTimeZone(window_start, 'America/New_York'))) < 960
GROUP BY d
),
averaged AS
(
SELECT
d,
px,
avg(px) OVER (ORDER BY d ROWS BETWEEN 19 PRECEDING AND CURRENT ROW) AS fast_ma,
avg(px) OVER (ORDER BY d ROWS BETWEEN 49 PRECEDING AND CURRENT ROW) AS slow_ma,
row_number() OVER (ORDER BY d) AS session_no
FROM daily
),
positioned AS
(
SELECT
d,
px,
if(session_no >= 50 AND fast_ma > slow_ma, 1, 0) AS long_today,
lagInFrame(if(session_no >= 50 AND fast_ma > slow_ma, 1, 0), 1)
OVER (ORDER BY d ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS long_prior,
lagInFrame(px, 1)
OVER (ORDER BY d ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS px_prior
FROM averaged
)
SELECT
toYear(d) AS year,
round((exp(sum(log(if(long_prior = 1, px / px_prior, 1.0)))) - 1) * 100, 1) AS next_bar_pct,
round((exp(sum(log(if(long_today = 1, px / px_prior, 1.0)))) - 1) * 100, 1) AS same_bar_pct,
round(abs(exp(sum(log(if(long_today = 1, px / px_prior, 1.0))))
- exp(sum(log(if(long_prior = 1, px / px_prior, 1.0))))) * 100, 1) AS gap_pp
FROM positioned
WHERE px_prior > 0
AND toYear(d) >= 2017
GROUP BY year
ORDER BY year
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