Palantir Technologies ( PLTR 9.79%) stock continued its winning streak on Thursday, climbing as much as 7.9%. As of 3:23 p.m. ET, the stock was still up 7.9%.

Palantir (Nasdaq: PLTR) opened Thursday trading slightly below where it closed yesterday. However, that situation quickly changed and its share price rapidly rose in early morning trading. For most of the afternoon,

The AI-focused Palantir joins a group of less than 50 public American companies worth at least $200 billion, quite the turn of events for the government contractor worth less than $20 billion two years ago.

While Nvidia stock is still pricey in many respects, it may have ceded the title of "Wall Street's biggest bubble stock" to AI-driven data-mining specialist Palantir Technologies ( PLTR -2.38%), based on what history tells us.

Key Takeaways Palantir Technologies shares soared to an all-time high Tuesday, a day after the company's outlook blew past analysts' expectations on strong demand for its Artificial Intelligence Platform.