There is no "law of conservation of money" and total asset values are definitely not conserved. See my recent diary on liquidity risk, How much is $172 trillion worth?

So, no, 90 million shares are definitely not worth 90 million times the share price, unless you can enter into a deal over the counter (off the exchange) with someone else who would like to own 1% of M$. And, most definitely, the entirety of the shares of Micro$oft are not immediately worth $271bn even though 1000-share lots (see the "bid" and "ask" in the Yahoo! Finance screen capture) can be quickly bought and sold at the share price.

When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes