RISK Time Risk · April 2026 · ~4 min

Holidays and daylight saving: two calendar traps

Two kinds of price weirdness have no explanation on the chart and an instant one on the calendar: holidays and daylight saving time.

Holidays: liquidity vanishes

• On US holidays (Thanksgiving, July 4th) the whole world half-hibernates — turnover collapses and spreads widen;
• On the last trading day before a holiday, institutions leave early; the afternoon drifts on fumes;
• Thin books raise the odds of extreme prints (flash moves, wicks) — don't carry weekday size into a holiday.

DST: the one-hour shift

Around March and November, the US and Europe switch daylight saving — data times, opens and overlaps all shift by an hour, and the two regions don't switch on the same date, leaving a misaligned week or two in between. Anchor on UTC or exchange time and audit your routine every March and November, and you'll dodge most "why did the data come an hour early" confusion.

When the chart can't explain a move, the calendar usually can.