Altman-Backed Oklo’s Shares Spiral in Debut After SPAC Deal (1)

Shares of Oklo Inc., a developer of advanced nuclear systems backed by Sam Altman, plunged Friday in its debut after merging with a blank-check company sponsored by the OpenAI chief executive and serial dealmaker Michael Klein.

Oklo tumbled 54% to $8.45 apiece in its debut on the New York Stock Exchange after completing a deal with AltC Acquisition Corp., which delivered more than $306 million in proceeds to the combined firm, according to a statement. The rough debut came as more than 25 million shares changed hands, more than 13 times what’s been typical over the ...