▁K ou m ▁convinced ▁Act on , ▁who ▁was ▁then ▁still ▁un emp loy ed , ▁to ▁join ▁the ▁company . ▁K ou m ▁granted ▁Act on ▁co - found er ▁status ▁after ▁Act on ▁managed ▁to ▁bring ▁in ▁$ 2 5 0 , 0 0 0 ▁in ▁seed ▁fund ing . ▁ ▁On ▁February ▁ 9 , ▁ 2 0 1 4 ▁Z ucker berg ▁asked ▁K ou m ▁to ▁have ▁dinner ▁at ▁his ▁home , ▁and ▁formally ▁proposed ▁K ou m ▁a ▁deal ▁to ▁join ▁the ▁Facebook ▁board . ▁ 1 0 ▁days ▁later ▁Facebook ▁announced ▁that ▁it ▁was ▁acqu iring ▁Wh ats App ▁for ▁US $ 1 9 ▁billion . ▁ ▁Over ▁the ▁first ▁half ▁of ▁ 2 0 1 6 , ▁K ou m ▁sold ▁more ▁than ▁$ 2 . 4 ▁billion ▁worth ▁of ▁Facebook ▁stock , ▁which ▁was ▁about ▁a ▁half ▁of ▁his ▁total ▁hold ings . ▁He ▁is ▁estimated ▁to ▁still ▁own ▁another ▁$ 2 . 4 ▁billion ▁worth ▁of ▁Facebook ▁stock . ▁ ▁On ▁April ▁ 3 0 , ▁ 2 0 1 8 , ▁K ou m ▁announced ▁that ▁he ▁was ▁leaving ▁Wh ats App ▁and ▁ste pping ▁down ▁from ▁Facebook ' s ▁board ▁of ▁direct ors ▁due ▁to ▁disput es ▁with ▁Facebook . ▁It ▁was ▁originally ▁thought ▁that ▁by ▁leaving ▁he ▁was ▁for fe iting ▁his ▁un v ested ▁stock , ▁worth ▁almost ▁$ 1 ▁billion . ▁However , ▁several ▁months ▁later ▁it ▁was ▁discovered ▁that ▁he ▁was ▁still ▁formally ▁employed ▁by ▁Facebook ,