The worth of the company is what someone will pay for it, although that gets fuzzy when "what someone will pay for it" is rather more than one person or non-governmental entity could raise, but there's no particular reason the market cap is that number. If someone makes a serious offer on a company, i.e., tries to buy all the stock, the stock price usually significantly rises. It has to; to pry the stock out of other people's hands you can't simply offer the market price, or they'd already have sold, so you can't just buy stock at the "market price" (as unaffected by your attempt to buy the company) and end up with all of it. Contrariwise, if someone owns a lot of stock and decides to just dump it all for cash, they won't get the market cap either, because the very act of dumping the stock will cause the price to go down, possibly even crash. So, the "market capitalization" is a "price" that you can neither buy, nor sell, the company for or at... so... it also can't be what "someone will pay for it", or, it isn't a "price" at all.