I worked at Parse when it was bought by Facebook. The day the news broke, Facebook’s market cap grew by multiples of the acquisition price. I remember being gobsmacked that Facebook effectively got paid to buy us.
Unless Facebook itself actually issued stock at the new price, Facebook did not get paid. It were the Facebook shareholders that got paid.
Really, it shows that the market valued Parse much more than the cash it cost Facebook. If Parse was bought with stock instead of cash, that's almost cooler. Since it allowed Parse to capture more of the surplus value they created. (Since the stock price popped).
More sophisticated analysis is required. You should look at the beta of Facebook at the time and determine whether the market reacted positively to the acquisition, or if the move was inline with Facebook's exposure to the market
