Have you noticed that sometimes market trading volume is abnormally crazy, and other times it’s surprisingly quiet? A large part of the reason behind this is actually due to quantitative trading.

Let's break it down. Suppose a quantitative team holds assets worth 2 trillion in market value. They decide to completely liquidate all positions that day, then buy everything back. Just this one buy and sell can contribute 4 trillion in trading volume. In another scenario, if they only sell 50% and buy back 50%, the trading volume contribution becomes 2 trillion.

The most flexible aspect of quantitative trading is here — they can dynamically adjust the daily turnover frequency and trading volume based on real-time market conditions. When market sentiment is hot, they might increase turnover. When the market is weak, they reduce the scale of their operations. This also explains why we often see trading volume suddenly spike one day and then plummet the next. The large fluctuations in trading volume are, to some extent, a reflection of how quantitative trading "breathes."