Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Facebook buying WhatsApp for 19 Billion. How are existing shareholders affected?
The answer to your question has to do with the an explanation of "shares authorized, issued and outstanding." Companies, in their Articles of Incorporation, specify a maximum number of shares they are authorized to issue. For example purposes let's assume Facebook is authorized to issue 100 shares. Let's pretend they have actually issued 75 shares, but only 50 are outstanding (aka Float, i.e. freely trading stock in the market) and stock options total 25 shares. So if someone owns 1 share, what percentage of Facebook do they own? You might think 1/100, or 1%; you might think 1/75, or 1.3%; or you might think 1/50, or 2%.  2% is the answer, but only on a NON-diluted basis. So today someone who owns 1 share owns 2% of Facebook. Tomorrow Facebook announces they just issued 15 shares to Whatsapp to buy the company.  Now there are 65 shares outstanding and 90 issued. Now someone who owns 1 share of Facebook own only 1/65, or 1.5% (down from 2%)! P.S. "Valuation" can be thought of as the price of the stock at the time of the purchase announcement.