Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Why does selling and then rebuying stock not lead to free money?
The main thing you're missing is that while you bear all the costs of manipulating the market, you have no special ability to capture the profits yourself. You make money by buying low and selling high. But if you want to push the price up, you have to keep buying even though the price is getting high. So you are buying high. This gives everyone, including you, the opportunity to sell high and make money. But you will have no special ability to capture that -- others will see the price going up and will start selling within a tiny fraction of a second. You will have to keep buying all the shares they keep selling at the artificially inflated price. So as you keep trying to buy more and more to push the price up enough to make money, everyone else is selling their shares to you. You have to buy more and more shares at an inflated price as everyone else is selling while you are still buying. When you switch to selling, the price will drop instantly, since there's nobody to buy from you at the inflated price. The opportunity you created has already been taken -- by the very people you were trading with. Billions have been lost by people who thought this strategy would work.