why can stocks be so volatile in after hours trading 
lower trading volume and less liquidity results when fewer traders and investors are in the market this causes wider bid ask spreads and in turn greater stock price volatility this is the challenging trading environment that can exist in after hours trading the bottom lineafter hours trading of securities occurs after the regular trading session closes at 4 p m et and can last until about 8 p m et while it offers investors certain advantages it also can be quite risky so in addition to understanding those risks be sure to consider your investing goals your risk tolerance and your trading style before getting involved most investors may want to stick with the familiar buy and hold strategy that can be executed during normal trading sessions however for those prepared for it after hours trading may be a useful investment tool and worth trying out 