Reading intraday volume at the open
Every Tuesday cohort eventually reaches the same question: price broke above the opening range, but should we trust it? Volume at the open is our first filter — not because volume predicts direction, but because thin participation tells you the move may not have commitment behind it.
Compare to a simple baseline
Before the session, note the average volume of the first fifteen-minute bar over the last twenty sessions. You do not need a complex indicator — a spreadsheet column or a quick eyeball of the chart history suffices. When today's opening bar prints at half that average, treat breakout attempts with scepticism until a second bar confirms with higher participation.
Watch acceptance, not just direction
Price above the opening high with declining volume often means the market is testing, not committing. In review sessions we ask: "Is volume increasing on each successive push?" If the third five-minute bar shows lower volume than the first, the breakout hypothesis weakens even if price still looks bullish.
Gap context matters
A gap-up open with low volume suggests fewer participants agreed overnight. We see participants chase the first green candle, then get reversed when European equities join with heavier flow. Mark the gap fill level before the open and note whether volume expands if price returns toward it.
A verbal checkpoint we use in sessions
Before stating a long bias above the opening range, say aloud: "Volume on the break is above or below my twenty-day opening average." If you cannot answer, you are not ready to complete the decision statement. This single pause prevents more impulsive entries than any indicator we could add to the chart.
What volume cannot tell you
High volume on a breakdown does not automatically mean short — it may mean capitulation near support. Volume confirms participation; it does not assign direction. Pair it with the levels you marked pre-market and the invalidation you stated before the bell.