If trade optimism is truly feeding these stock records, then get the confetti ready.

Reports that the U.S. may drop some China tariffs to seal a “phase one” deal are boosting stock futures on Tuesday. That’s a day after all three major U.S. indexes nailed record closes.

But Lori Calvasina, RBC Capital Markets’ head of U.S. equity strategy, is wary of those highs and offers five reasons why investors should be too, in our call of the day.

In a note to clients, she says she’s sticking to RBC’s year-end S&P 500 SPX, -0.04%  target of 2,950, even as the index pushes above 3,000. Here’s why: