The major stock rally after the U.S. presidential election is over, and investors should employ a new strategy to make money, closely followed strategist Mark Grant, who predicted the postelection rally, told CNBC on Monday.

The chief strategist at Hilltop Securities said he changed his investing strategy after it became apparent that President Donald Trump would continue to get pushback as he attempts to "drain the swamp."

"You're seeing an outsider as the president ... (who) wants to run the country in a business-like fashion and you're seeing all the insiders, the bureaucrats, the lawyers, the lobbyists, the Democrats, pushing back because the guy is trying to radically change the system," Grant said on "Squawk Box."

"The big equity run is over," he added.

Grant's remarks came nearly two weeks after Trump sparked an uproar by firing former FBI Director James Comey and almost a week after allegations he asked Comey to stop investigating his former national security advisor, Michael Flynn.

Grant said on the morning of Election Day in November that investors would be smart to buy stocks in the event of a surprise Trump victory.

That advice sure paid off. Since the election, the Dow Jones industrial average has surged more than 13 percent, the S&P 500 has gained 11 percent and the Nasdaq composite has risen 17 percent as of Friday's close.

On Monday, U.S. stock index futures pointed to a slightly higher open as Trump travels around the Middle East, and Fed policymakers are scheduled to speak this week. The central bank on Wednesday will publish minutes of its May meeting.

Also on "Squawk Box," James Liu, founder and head of research at Clearnomics, said the Fed is considering whether the turmoil in Washington will significantly impact the markets.

"The Fed is going to keep raising rates," he said. "The big question for the Fed is are the things happening in Washington and the scandals there ... is that crippling enough to derail the markets?"