Trump Media & Technology Group stock racked up major gains last week, but investors shouldn’t expect this rally to last much longer. The shares’ wild moves this year tell the story.

Trump Media, which trades under the stock ticker DJT in reference to President Donald Trump’s initials, closed down 10.4% at $14.41 on Monday. Earlier, it surged as much as 5% in the premarket, and was at one point the second-most traded stock by total volume, behind chip maker Nvidia.

DJT surged 42% on Thursday, netting the Trump family more than half a billion dollars in paper gains in a single trading session, powered by investors’ excitement about the Truth Social parent’s unusual merger with nuclear fusion company TAE Technologies. It rose another 8.3% on Friday.

The two companies are combining in an all-stock deal valued at more than $6 billion to build fusion power plants that will help meet the demand for electricity created by the rise of artificial intelligence.

Investors should be wary. No Wall Street analysts cover Trump Media right now. A big bet the company has made on Bitcoin already appears to have gone sour, and it reported a net loss of $54.8 million over the third quarter. Shares are still down 53% for the year despite the recent rally.

There is also plenty of uncertainty about the future of nuclear fusion. Barron’s argued last week that the most likely outcome is that the stock’s gains fade as timelines for fusion technology get stretched out, costs rise, profits prove elusive, and capital gets harder to raise.

It isn‘t as if the shares have ever traded on Trump Media’s underlying fundamentals. They tended to serve as a proxy for Trump’s popularity in the run-up to the 2024 presidential election, before giving up all of those gains.

DJT stock might still make sense for day traders looking to trade off the volatility, but investors planning for the longer term should tread carefully.