We often hear how traders use volume to confirm "strength" of the market e.g. down on increasing volume is good as it signals buyer support. Question. In todays environment of black box trading, trades held for seconds and minutes at a time (day trading churn), is volume a false indicator? Looking back last Friday yeah the NYSE volume was up - but so what. If black boxes were simply churning (buy/sell/buy/sell) throughout the day as the market whipsawed what use is volume apart from a liquidity indicator.