"When you have a president who grades himself by how stocks do, you know he's just not going to hurt the market," Cramer said Wednesday on "Squawk on the Street." "Most of the president haven't really cared about the market."
"It's been a great run," the host of CNBC's "Mad Money" added.
Since the Nov. 8, 2016, election, the Dow Jones industrial average has risen more than 28 percent as of Tuesday's close. The S&P 500 has gained more than 21 percent and the Nasdaq is up more than 30 percent.
Trump has repeatedly claimed credit for the stock market rally. Some analysts have attributed the market rise to Trump's planned tax reform and other business-friendly proposals, though some argue they haven't had a real influence.
At the first anniversary of Trump's election, the subsequent stock market's gain ranks No. 3 in first-term, postelection markets since the Eisenhower days, according to a CNBC analysis.