What was Facebook's largest acquisition by deal value?
Answer
Facebook's largest acquisition by deal value was WhatsApp.
Facebook agreed to acquire WhatsApp on February 19, 2014, in a transaction valued at approximately $19 billion when announced. The deal consisted of cash, Facebook shares, and restricted stock units for WhatsApp employees and founders. After the transaction closed, the final value was often reported at roughly $19.3 billion because of changes in Facebook's share price.
WhatsApp was founded in 2009 by Jan Koum and Brian Acton and had become a major mobile messaging service before the acquisition. Facebook said the app would continue operating as a separate service, preserving its brand and core messaging experience.
The acquisition is commonly confused with Facebook's purchases of Instagram or Oculus VR. Instagram cost about $1 billion, while Oculus VR cost about $2 billion—both substantial deals, but far below WhatsApp's value at the time. The question asks about deal value, not the number of users or strategic importance.