The Trump rally is on its last legs, and according to one strategist, that means stocks could see a huge drop in the coming months.

Since the election, the S&P 500 Index has rallied more than 6 percent while the Nasdaq hit another record intraday high on Friday. Meanwhile, the Dow Jones Industrial Average continues to hover just under the 20,000 level, underscoring what some analysts believe is a market that's starting to look too frothy.