Trading Volume

What is Trading Volume? — Definition

Volume measures how many shares changed hands during a specific time period. High volume on a price move confirms the move is significant — many participants are acting on the same information or conviction. Low volume on a price move suggests it may be weak or unsustainable — driven by thin trading rather than broad conviction.

Key volume patterns: a breakout to new highs on high volume is bullish. A rally on declining volume may signal exhaustion. A stock falling on high volume is bearish — institutions may be distributing (selling) a large position. Volume tends to spike during major catalysts: earnings releases, M&A announcements, or macro events.

Example

When Nvidia reported earnings in May 2023 with explosive AI guidance, the stock gained 24% in a single day on trading volume that was 8x the 30-day average. This massive volume confirmed that institutional investors were aggressively buying — not just retail speculation.

BMInsider's market tools track abnormal volume signals, and the Smart Money Tracker cross-references volume spikes in tracked stocks with subsequent 13F filings to identify potential institutional accumulation.