Donald Trump’s election helped turbocharge an already surging bull market in the U.S., sending stocks and cryptocurrencies to record highs.

Now, some on Wall Street are beginning to sound the alarm that the fast times can’t last.

JPMorgan Chase CEO Jamie Dimon and others have warned that investors are plowing cash into stocks with inflated prices. Hedge fund giant Elliott Management said the blistering rise in crypto over the last year, with bitcoin up 89 percent, is the stuff of bubbles. So-called memestocks — companies like GameStop, whose shares tend to be driven by investor hype — have returned. And on top of that, economists say Trump’s plans for tariffs and an immigration crackdown — along with the dizzying pace of his policy moves — could roil the markets by stoking inflation and fueling uncertainty.