Measured, not guessed · 2020..2026 of H1 data

When does SPX500 actually rise?

Every hour below is a real measurement: how often SPX500 closed higher than it opened in that hour of the week, across 38,939 hourly bars. Not signals — base rates, with the sample size on every figure.

The strongest and weakest hours

Averaged across the trading week, the hour that has leaned up hardest is 18:00 UTC — SPX500 closed higher 54.2% of 1,654 times there, far enough from a coin flip to be beyond chance. The weakest is 21:00 UTC, closing higher only 46.3% of 551 times.

Hour × weekday, the whole picture

Colour is the up-rate — red leaned down, teal leaned up. The brass dot marks buckets whose lean is statistically beyond chance at |z|≥3. Most cells have no dot. That is the honest shape of the market: mostly noise, with a few stubborn corners.

The three most stubborn corners of the grid:

• Monday 18:00 UTC — closed higher 59.1% of 308 times (z=3.2)
• Monday 17:00 UTC — closed higher 58.5% of 323 times (z=3.1)

Days and seasons

Weekday	Up-rate	Sample
Monday	54.1%	n=7,675
Tuesday	50.7%	n=7,884
Wednesday	52.2%	n=7,850
Thursday	52.3%	n=7,831
Friday	52.0%	n=7,134
Sunday	51.7%	n=565

Monday has been the friendliest day (54.1% of 7,675), Tuesday the least (50.7%). By calendar month, November leads at 52.9% and December trails at 50.5% — month buckets carry roughly a twelfth of the sample each, so hold them more loosely than the hourly figures.

Did any of it survive a real backtest?

Colours are description. A different question is whether a simple rule built on them — enter at the open of a bucket, exit at its close, pay a realistic spread — would have made money, and kept making it on data it was never fitted to. We ran that test across 5,086 rules on the whole board: 307 finished net positive, and only 214 survived the held-out final third of the history.

None of the survivors run on SPX500 once spread costs are charged. The strategy board shows that too — a leaderboard that only shows winners is lying by omission.

Watch it live

These are the same numbers, updating as each hour begins — free to embed on your own site from the widget builder:

Read it without fooling yourself

• The percentage is the headline, not the story. 54.2% from 1,654 samples is information; the same figure from 40 samples is noise. Every number here carries its n.
• The dots matter more than the colours. A vivid cell with no dot is well inside what chance produces.
• Direction is free; getting paid is not. A reliable lean smaller than your spread costs more than it earns.
• These are frequencies, not forecasts. 5 years of "usually" contains every kind of "except when".

The guide walks through all four traps with live numbers.