After another week of roller coaster market action, investors may be looking at the balance in their 401(k) plan and wonder what they should do about their retirement savings.

The volatility in the U.S. and global equity markets has led some "buy-and-hold" investors to make major moves in their retirement plans.

Daily trading activity in 401(k) plans was more than double the normal level at the end of October, as the S&P 500 index tumbled and investors moved away from equities into fixed income, according to Alight Solutions.

Daily 401(k) trading jumped again recently as the markets rebounded and investors moved back into equities, and stabilized a bit this week. While this daily trading activity represents a small fraction of total 401(k) balances in the U.S., data from Alight shows the past few weeks have seen some of the highest levels of trading since mid-April.

However, Investors may be buying and selling in their 401(k)s on emotion instead of based on their financial goals, says Rob Austin, vice president of research at Alight.

"Rather than making a knee-jerk reaction to market swings in either direction, investors need to have an investment strategy in place that helps meet their short-and-long-term goals," Austin said. "They need to stick to that game plan, even when times are tough." Often, that doesn't happen.

Legg Mason surveyed 1,000 investors last summer who had at least $50,000 in investable assets. Nearly one in three investors admitted to making an emotional decision to sell in a 401(k) plan that they later regretted. And almost half of those who sold described their investment knowledge as "expert or advanced."

No matter how much you know about investments, poor choices in other areas can do even more damage to your retirement. "More often than not a 'retirement fail' is caused by decisions that bring immediate gratification but long term don't help you achieve what you most desire, mainly happiness and security," said financial advisor and "Retirement Fail" author Greg Sullivan.