Investors like Andrew Skillman remained calm and held firm during market slumps caused by the trade war. Skillman, a 60-year-old investor, emphasized the futility of timing the market and the importance of staying composed. Despite past experiences during crises like 9/11 and the 2008 financial crisis, Skillman learned to react less and avoid panic selling. This approach led him to benefit from market rebounds and avoid missing out on opportunities. The article highlights the resilience and strategic mindset of investors in navigating market uncertainties.