Jan Koum may be leaving Facebook Inc. but that didn\u2019t stop him from getting stock awards this week worth $458 million. The co-founder of WhatsApp, a Facebook messaging unit, had 2.5 million shares vest Tuesday, with about half withheld to satisfy tax obligations, according to a regulatory filing. Koum\u2019s Butterfly Trust sold the rest on Wednesday. Koum, 42, confirmed in an April 30 Facebook post that he\u2019s leaving the social-media giant, without saying exactly when that will happen. He won\u2019t stand for re-election to the board at the firm\u2019s May 31 annual meeting, the company said in a filing. A Facebook spokeswoman declined to comment. Koum still owns 4.6 million restricted shares, which vest in August and November. The awards are contingent on him being employed through those dates unless his exit is categorized as an involuntary termination or resignation for good reason, regulatory filings show. Facebook shares rose 0.6 percent to $183.80 at 10:51 a.m. in New York, bringing this year\u2019s advance to 4.2 percent.