Stocks jump as turnover plunges

Major ETFs like SPY and QQQ jumped by more than 1.5% on Monday on volume that was about half (or less) what it was on Friday. This is usually considered a negative. For SPY, it has rallied more than 1.5% on volume that dropped by 40% or more 17 times since 1993. Its worst returns were 3 days later, with a 41% win rate and -0.3% average return. After that, returns were mixed. For QQQ, it triggered 24 times, with returns that were about in line with random going forward until 2-3 months later when they were weak. This type of activity tends to happen during bear markets, so results skew toward the negative.