US stock markets face predictable volatility every Thursday and Friday, with the S&P 500 down 9% cumulatively since the war began on those days. This pattern stems from investors de-risking ahead of weekend trading blackouts, fearing unforeseen events like President Trump's potential market-moving gambits. The phenomenon intensifies during long weekends, such as the current Good Friday closure, when critical reports like the monthly jobs data emerge while markets are closed.

Experts note the psychological impact: 'It has become easier to de-risk going into weekends than to hold positions,' says Joe Gilbert of Integrity Asset Management. This forced selling creates a self-reinforcing cycle where uncertainty breeds caution, directly impacting market stability.