Research · a claim, tested

Does the first hour set the day?

Two reports this category sells by name, and they are the same question twice: opening candle continuationif the first hour is green, how often does the session close green? — and the initial balance, the first hour's high and low. We ran both on 68,678 sessions across 17 markets. One of them finds nothing at all; the other fires on 99.7% of days.

-0.12points a green first hour is worth, over its control
0/17markets reaching even |z| = 2
0.33%of sessions leave the initial balance unbroken
68,678sessions measured

Where the open is

Before any of this can be measured you have to decide what "the first hour" means, and getting that wrong is how the naive version of these reports goes wrong. There is no first hour of a currency day in UTC. So FX and metals use the London open and the index markets use their own cash open, both resolved through each city's clock for every single day so daylight saving cannot shift them. Crypto is excluded: it has no open, and inventing one is exactly the mistake to avoid.

Continuation, and the control that kills it

The obvious way to test this is to count: of the days whose first hour closed green, how many closed green overall? That number will land somewhere near 50% and look like something. The control is what makes it readable — we re-pair each day's first hour with a different day's session. The same number of green first hours, the same number of green sessions, and the link between them destroyed.

There is no effect anywhere. The median market beats its control by -0.12 percentage points, the median z is -0.14, and not one of the 17 markets reaches even |z| = 2 — the strongest anywhere is Gold (XAU/USD) at 1.46. This is the flattest result we have published. A green first hour tells you that the first hour was green.
MarketSessionsGreen first hour → green sessionControlΔzOne side of the IB breaksControlNeither side
EUR/USD5,914 48.3%48.5% -0.1-0.14 47.2%44.9%0.27%
GBP/USD5,218 50.4%49.6% +0.80.78 47.0%44.5%0.33%
USD/CHF3,240 51.1%51.4% -0.3-0.26 46.3%44.4%0.37%
USD/JPY4,574 52.5%52.0% +0.40.44 46.6%43.5%0.42%
AUD/USD5,721 48.8%49.1% -0.4-0.42 45.1%43.9%0.14%
USD/CAD5,931 49.1%50.0% -0.8-0.93 34.9%35.7%0.05%
NZD/USD5,169 50.3%50.4% -0.1-0.15 44.4%43.8%0.10%
EUR/JPY5,239 50.6%50.4% +0.20.22 51.5%48.5%0.52%
GBP/JPY4,171 52.9%52.1% +0.80.72 50.6%47.2%0.26%
EUR/GBP2,454 47.4%47.8% -0.4-0.24 48.1%47.1%0.20%
Gold (XAU/USD)6,043 51.8%50.5% +1.31.46 37.2%35.2%0.13%
Silver (XAG/USD)5,187 52.6%53.1% -0.5-0.56 32.4%35.5%0.04%
US30 (Dow)2,811 51.9%53.2% -1.3-0.98 68.1%67.8%1.89%
NAS1001,663 57.0%56.2% +0.90.5 70.3%69.9%2.41%
SPX5001,663 55.3%53.8% +1.50.89 66.2%65.9%1.56%
GER40 (DAX)2,711 52.8%52.7% +0.10.06 63.1%62.0%1.25%
UK100 (FTSE)969 49.7%51.9% -2.2-1 63.8%62.0%0.52%

The initial balance fires on almost every session

The first hour's range survives the rest of the session untouched on a median of 0.33% of days. A filter that admits 99.7% of sessions is not a filter — it is the same defect the opening range has, and it is fatal in the same way.

The half that does survive is the split between a session that breaks one side and one that breaks both — the trend-day story the report is really sold on. One side only happens on a median 47.23% of sessions against 44.94% for a session that keeps its own bars, its own hours and its own sizes and loses only their direction. That is a real gap of +1.16 points — and it is smaller than every spread on our board.

The control matters more here than anywhere else in this series. A bigger session breaks a range more often for reasons that have nothing to do with the opening hour, so the naive version of this statistic is largely a volatility measurement wearing a pattern's name.

What we would actually say

Full method and every market in section 20 of the evidence page.

Other reports this category sells, tested

Do weekend gaps fill?"Gaps fill 90% of the time" is true and empty — a matched midweek move fills just as often. The indices do the opposite.Does yesterday's high or low matter?68,688 breaks across 19 markets. The level holds 50.4% of the time — slightly less than an arbitrary level the same distance away.Does the opening range set the day?The range breaks on 99.8–100.0% of days. A signal that fires every session has not selected anything.When does the day's high and low actually form?"The high forms at the open" is the boundary you chose, not the market. Move it and every single market changes its answer.Does the trading day of the month matter?The chart this whole category is built on. 285 slots tested, 0 clear the bar, and the strongest anywhere reaches z = 2.99.The best time to trade forexThe overlap is real — as a movement and cost argument, not a direction one. The half that survives a holdout is WHEN, not which way.Does Bitcoin move on the weekend?The weekend is an ordinary trading period whose timetable is a different timetable — the biggest hour moves from 14:00 to 00:00 UTC.

Every claim we have tested, including the ones that held, is on the reports index.

We publish the tests that failed as loudly as the ones that held. Every number on this site carries its sample size, and every claim carries what it was measured against.

Read the whole evidence page →