(Reuters) -Tech billionaire Peter Thiel's hedge fund has sold off its entire stake in Nvidia ( NVDA ) during the third quarter, a regulatory filing showed, intensifying worries of an artificial intelligence bubble.

The fund, Thiel Macro, sold around 537,742 shares in the AI chip frontrunner in the quarter, the filing showed on Friday. The stake would have been worth around $100 million, as of the company's closing price on September 30.

Thiel's selloff, coupled with SoftBank's sale of its own Nvidia ( NVDA ) holdings last week, has fueled Wall Street's angst that the frenzy driving soaring tech valuations may have peaked, putting at risk the trillions of dollars committed to AI advancement.

Investors and analysts will be looking to Nvidia's ( NVDA ) third-quarter results on Wednesday to dispel worries of a bubble as the world's most valuable company is considered a bellwether for AI demand due to its coveted chips being used in massive data centers and servers.

Thiel Foundation did not immediately respond to a Reuters request for comment.

In the third quarter, several hedge funds trimmed their stakes in some of the largest seven tech firms, also called the "Magnificent Seven", in a shift from their second-quarter activity, when leading stock-picking firms were more bullish on Big Tech names.

Thiel's fund now counts Apple, Microsoft and a reduced stake in Tesla as its main holdings, according to the filing with the Securities and Exchange Commission.