Palantir was the best-performing member of the S&P 500 ( ^GSPC -0.01%) during that period. In fact, it beat the next closest stock by 250 percentage points. But Palantir is now one of the most expensive software stocks in history, and there is little questions about what happens next: One way or another, it's valuation is going to fall.

Shares of BigBear.ai (NASDAQ:BBAI) rocketed 21% higher last week and are up 133% in 2025. The data analytics shop has climbed five times higher in the past 12 months, rising from under $2 a share to almost $10 a stub.