Research notes, with the sample size attached
Every number on these pages carries the window it was measured over, how many observations it rests on, and what it was compared against. Where a control group exists it is stated; where the sample is too small to support a claim, that is stated instead.
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Claims retail traders inherit — tested
The calendar effects are real and still useless
Thursday is the widest median day on SPY and QQQ. The weekday spread is a fifth of the daily one.
Before you read any indicator
When futures actually trade
One contract, five different closing times — and trading ends at 9:30 a.m. on expiry day, not at the close.
Best time of day to buy an ETF
SPY's busiest hour is 2.21x its quietest — and it is also where the price bands are widened.
Trading ETFs premarket and after hours
64.3% of SPY's after-hours volume lands in fifteen minutes, and the circuit breakers are off.
The overnight gap is mostly over before you see it
A median 60% of SPY's gap was already done at 04:01 — and all six instruments agree.
Every note, in one list
The grouped view above is the reading order. This is the plain index — and the RSS feed and sitemap carry the same set for anything reading this page automatically.
- The calendar effects are real and still useless
- When futures actually trade
- Best time of day to buy an ETF
- Trading ETFs premarket and after hours
- The overnight gap is mostly over before you see it
See these levels on a live chart
Option-derived levels and futures tape on one timeline.