Michael Klein is one of those investment bankers that most people have never heard of, but IYKYK. Klein, after all, has been a certified bigwig since his days at Citigroup, back when it was the powerhouse on Wall Street. He’s advised on any number of high-profile deals, including Barclays’ acquisition of some of the Lehman Brothers assets; IHS’s merger with Markit; and the creation of Dow-DuPont. Now, at 57, he is the proprietor of his own shop, a boutique investment bank and advisory firm named M. Klein & Company, and has his hands in virtually all the dealflow, often in both creative and controversial ways. 

For instance, starting in 2018, Klein became infatuated with the now-dead SPAC mania. Through a shell company called Churchill Capital Corporation—he’s an Anglophile, like many of these guys—Klein raised $7 billion and “sponsored” seven different SPACs. His most well-known SPAC deal, Churchill Capital IV, ended up merging with Lucid Motors, the electric car manufacturer, in July 2021, at a valuation of $14 billion. It’s now trading for around $8 billion, down 89 percent from its high in November 2021. He also raised $690 million for another Churchill fund that he merged with Clarivate Analytics, in May 2019. Its value is around $6.2 billion these days, down one-third since the merger.