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.

Palantir Technologies Inc. (NASDAQ:PLTR – Get Free Report)’s stock price was up 25.2% during mid-day trading on Tuesday after Citigroup raised their price target on the stock from $42.00 to $110.00. Citigroup currently has a neutral rating on the stock.

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.

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%.

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.