← All tested claims

Should You Avoid Trading on Monday?

Mostly false — and backwards for indices.

Monday is unremarkable in FX. In the two most-traded US indices it is mildly favourable: SPX500 closed higher 54.1% of Monday hours against 51.8% the rest of the week. The advice is repeated as universal and points the wrong way for the markets where it is testable.

What the data shows

Across 19 markets: direction: 2 of 19 markets differ beyond chance · movement: quieter in only 7 of 19. Median movement in the window, 95% of a normal hour.

This claim is about how much the market moves, so the six shown are those whose movement changed most — not those whose direction did. The direction column is kept beside it because a claim about activity is often repeated as if it were about direction.

Who says it

BrokerXplorer · BabyPips forum

How this was measured

Every claim here reduces to a window on the clock or the calendar, so it can simply be checked. We compare the claimed window against the rest of the week on 23 years of hourly data across 19 markets, measuring two separate things the folklore tends to conflate: direction (does the window close higher more often?) via a two-proportion z-test, and movement (is the average move bigger or smaller?). A window can be perfectly ordinary in direction and genuinely quieter in movement — saying which is the entire point.

The bar here is |z| ≥ 2, deliberately more lenient than the |z| ≥ 3 this site applies to its own numbers: when testing someone else's claim, failing to reject it even at a lenient bar is the stronger statement.

Check any hour yourself →

Free on the four major pairs, with the full 23 years and the sample size on every number.