Most people think the stock market is a zero sum game because there is a buyer for each seller and seller for each buyer so each cancels the other and everything is equal. Not quite.

There are losers here, both the buyer and the seller because each one paid a commission to buy and a second commission to sell. This eats away at the profit of the winner and adds to the loss of the seller if he sold for less than he paid.

How does buying and selling of a stock effect the company? When you buy GM stock from your broker he is completing a transaction between you, the buyer, and someone else, the seller. The company has nothing to do with the transaction other than change the name of the shareholder on their record books. It has no effect on the corporation