Legendary investor Bill Miller says the window is closing on the SPAC market, but singles out 2 names that remain attractive

• Bill Miller says the SPAC craze may be winding down, and that many have "extraordinarily expensive valuations".
• "I think that game is largely winding down now," Miller told CNBC.
• But the billionaire named two specific names that remain attractive.

Legendary investor Bill Miller thinks the SPAC craze may be nearing the end.

Pushed by a frenzy of excitement from retail investors and a desire from many pre-revenue companies to take an easier path to public markets, SPACs have boomed in 2020 and 2021.

"I think that game is largely winding down now," Miller told CNBC on Tuesday. "Many of the SPACs that came public came at extraordinarily expensive valuations. But now some of them have corrected."

The billionaire pointed to some SPACs that now have more reasonable valuations, such as Desktop Metal, a 3D metal printing technology provider that famed investor Chamath Palihapitiya also backed. The company went public in a merger with blank check company Trine Acquisition. The stock peaked at $31.25 on February 1 before tumbling to $12.70 as of April 20.

Miller also said he likes Metromile, a US-based pay-per-mile insurance technology that merged with SPAC Insu Acquisition in February. The billionaire called it the "next wave of insurance company." Metromile shares have tumbled 50% since their public debut.

Miller also named specific stocks including Amazon, Alphabet, Facebook, and Apple, which he said his fund no longer owns.

He also singled out online car dealer Vroom.

"That's the name we think you could make multiple times your money in the next three or four years," he told CNBC.

SPACs, shell companies seeking to merge with private companies with the intention of taking them public, have boomed. In 2020, a total of 248 SPACs raised $83.3 billion according to SPAC Analytics. But by the fourth month of 2021 alone, 308 SPACs have raised $99.7 billion, comprising 65% of all IPOs.

Recently however, US regulators have said they will take a closer look at SPACs following the blistering pace of growth over the last year.

Paul Munter, the acting chief accountant at the Securities and Exchange Commission, in April cautioned SPAC investors about the risks and governance issues that come with raising capital through blank check companies.

In March, the SEC has begun an inquiry into the SPAC craze, seeking voluntary information from market participants.