We quickly put together a table of the return on the Dow Jones Industrials Average after the first 100 days of presidential administrations, the return on their Inauguration Day, and the return the day before the inaugural going back to William Howard Taft. We included only newly inaugurated president (first term) and left out those who assumed the office mid-term either through tragedy or scandal.
It is safe to say that no president has, and probably never will, beat FDR’s performance unless the country experiences a bout of hyperinflation or another depression. Roosevelt declared a bank holiday as soon as he assumed office and the stock market was closed for several days until Congress could act on legislation.
…The banking system was on the verge of collapse. On March 4, Delaware became the 48th and last state to close its banks.  Following his inauguration on March 4, 1933, President Franklin Roosevelt set out to rebuild confidence in the nation’s banking system. On March 6 he declared a four-day banking holiday that kept all banks shut until Congress could act.
…The EBA [Emergency Banking Act] was one of President Roosevelt’s first projects in the first 100 days of his presidency.
…Within two weeks, Americans had redeposited more than half of the currency that they had squirreled away before the bank suspension. The stock market registered its approval as well. On March 15, 1933, the first day of stock trading after the extended closure of Wall Street, the New York Stock Exchange recorded the largest one-day percentage price increase ever with the Dow Jones Industrial Average gaining 8.26 points to close at 62.10; a gain of 15.34 percent. – Wikipedia
Interestingly, George H.W. Bush first 100 days (approximate trading days) saw the Dow’s highest return of the modern day presidents. Thoughts and prayers go out to the President and the former First Lady as they recuperate from their recent illness. What great people, full of grace, dignity, and class.