You've got the right idea, but picked the absolute wrong stock for your illustration. Apple's current market cap, i.e. shares outstanding times share price, is

You've got the right idea, but picked the absolute wrong stock for your illustration. Apple's current market cap, i.e. shares outstanding times share price, is approximately $866 billion dollars. Apple traded 21,583,997 shares today. Aggressively selling 500,000 shares (less than $100 million dollars worth) might move the market in this stock by perhaps 1%, certainly not anywhere near 10%.