In the heat of a market crash, the "red" on your screen can feel like a physical weight. Whether it’s a sudden 10% dip in stocks or a 40% "flash crash" in crypto, the psychological toll is real. However, history shows that for retail investors, the most expensive mistakes aren't made by the market—they are made by the investor in the moments following a crash. $Invesco QQQ(QQQ)$ $SPDR S&P 500 ETF Trust(SPY)$ $iShares Russell 2000 ETF(IWM)$ $Straits Times Index(STI.SI)$ $SPDR Gold ETF(GLD)$ $NVIDIA(NVDA)$ Here is a practical guide on h