How a stock split works
When a company decides to split its stock, it typically issues a press release that outlines the key details of the split. For example, this will include the ratio of the stock split (i.e., how many shares you'll receive for each one you own), as well as the effective date of the split, which is when the stock will begin trading on a split-adjusted basis.
On the effective date of a stock split, the share price will be proportionately reduced, and the additional shares will be credited to investors' accounts. If the company completes a 10-for-1 stock split, and you owned 20 shares worth $1000 each prior to the split, you would now own 200 shares worth $100 each.