Panic selling not only locks in losses but also puts investors at risk for missing the market's best days.
Looking at data going back to 1930, Bank of America found that if an investor missed the S&P 500's 10 best days in each decade, total returns would be just 91%, significantly below the 14,962% return for investors who held steady through the downturns.
The firm noted this eye-popping stat while urging investors to "avoid panic selling," pointing out that the "best days generally follow the worst days for stocks."
Looking at the Dow Jones Industrial Average as a reference point, this pattern could be seen playing out this week. The 30-stock index posted sizable losses on three days this week, but it also enjoyed the two largest daily point gains on record and ended the week with a 1.8% gain.
Experts advise investors to avoid the impulse to time the market, which can be difficult even for professional traders.
Still, retail investors like to try. The popular trading app Robinhood recently experienced "an unprecedented load" that caused outages Monday and Tuesday. The outages prompted outrage on Twitter and at least one lawsuit from a trader claiming to have missed out on Monday's rally.
The stock market, meanwhile, remains in correction territory with the major averages all down more than 12% from their highs.
The Bank of America strategists, led by Savita Subramanian, noted that corrections are common. The firm said that a correction has occurred once a year on average since 1928, and that losses are typically recovered over the subsequent three months.
Additionally, the strategists don't see a bear market on the horizon. Currently 53% of the firm's bear market signposts are triggered. The list includes factors like consumer confidence and monetary policy. Since 1960, more than 80% have been triggered ahead of prior market peaks.
That said, as the coronavirus outbreak continues to roil global markets, the firm is not as bullish as it was. On Monday, it cut its 2020 earnings per share estimate on the S&P 500 by 5%, while also lowering its 2020 year-end target on the index to 3,100.
"Negative headlines and panic selling are not good reasons to sell, but the coronavirus outbreak is now meaningfully impacting fundamentals," the firm said.
For investors who feel they have to do something during downturns, TD Ameritrade chief market strategist JJ Kinahan advises to make only small moves. "The problem most people have is they think all or none: think partials," he said.
"This also goes for the opportunities in the market. That is, if you see a stock at a level you like, you could buy some but perhaps not all," he added. "If the stock goes down you have an opportunity to buy more at a better price."
- CNBC's Michael Bloom contributed reporting.
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