President Donald Trump last month tanked the American stock market when he sent out a series of unhinged tweets ordering American companies to come up with new places to manufacture their goods outside of China.
And according to new research from Bank of America Merrill Lynch, the president's angry tweeting is having a negative impact on the stock market, and thus millions of Americans' 401(k) funds.
MarketWatch reports that the bank recently "studied daily returns for the S&P 500 on days when Trump writes more than 35 tweets in a day, versus those where he types fewer than five of them."
The difference between high-volume tweeting days and low-volume tweeting days was stark, and MarketWatch said that the researchers observed "a 9 basis point drag on days where Trump is pounding out tweets fast and furious versus a 5 basis point tailwind on days where he mostly stays off the platform."
The Bank of America researchers say that there is no way to predict when the president will unleash an angry, market-rattling tweet storm, so they advise investors to "trade cautiously" as long as he's in the White House.