Stock market falling? Here's what that means for your 401(k).

When the stock market falls, your first instinct might be to panic. But now is the time to follow the cardinal rules of investing.

Armchair investors have endured several stomach-churning days in March, with the S&P 500 and Dow Jones averages seesawing in response to the Iran war, surging gas prices and inflation fears.

When the stock market falls off a cliff, the natural impulse might be to panic and sell. There’s nothing so worrisome as watching your 401(k) sink into the red, with no bottom in sight.

But panic-selling violates two or three cardinal rules of investing: Buy stocks when prices are low, sell when they’re high. Don’t make impulsive moves. Stick to the plan.

Here are a few rules to remember when markets are reeling:

It might sound tempting to cash out of the stock market when the indexes are falling, sit out the downturn, and reinvest when markets hit bottom.