From BPNYA chart below, it is apparent that if market keeps going down further then soon we should get a SELL signal (BPNYA crossing EMA(30) downwards). Since we do not have enough confidence in current market action, its wise to remain on sidelines and NOT remain invested.
401K/HSA/College Fund: Market is very volatile and hence risky to remain invested at this time. Best strategy is to move money into money market fund for now. If for some reason you still haven't moved your money to money market fund then remaining invested further is very risky especially if we get another sharp decline.
Traditional IRA/Roth IRA: Be careful as the market is very volatile. Just follow BUY/SELL signal as no trading restrictions are applied on these accounts. Choose ETFs based on the strategy provided here.