President Donald Trump's first 100 days in office are the worst for the stock market for the start of a president's four-year term since the 1970s. The S&P 500's 7.9% drop from when Trump was sworn into office on Jan.

President Donald Trump's first 100 days in office delivered the worst start for stocks since former President Richard Nixon's second term in 1973, stoked volatility across markets and created expectations of a semi-permanent state of uncertainty.

The stock market tumbled by the largest amount in a president's first 100 days in office since Richard Nixon's second term began in 1973 under Donald Trump, new research shows.