The S&P 500 has rallied 5.5 percent since Donald Trump's inauguration, putting the market on track for its third-best performance during a president's first 100 days since World War II, according to CFRA analysis.
The U.S. hasn't had a post-inauguration gain this large since President George H.W. Bush's early days, when the market rallied 7.7 percent. The post-World War II crown for best market gain, however, goes to John F. Kennedy. During his first 100 days, the market jumped 9 percent.