For example, lets say Bob owns $1m of stock in company X and Alice is his willing accomplice. The stock is currently trading at $100/share. Bob then puts out his stock up for sale at $200/share, which Alice promptly purchases. She then puts them up for $300/share, which Bob buys. Then keep going until you've reached $1000, raising the stock price 10-fold artificially.
What is the name for this tactic and what stops it from happening in practice?