A stock split is an event similar to when a company issues a dividend. By this we mean the company’s board of directors first announces its intention to split the company’s stock. At this time, the board makes four announcements:
The stock split ratio - The most common ratios are 2:1 or 3:1. However, as shown in our prior example, companies can announce whatever split the board agrees to.
The split record date - Like a dividend record date, this is the date on which an investor must own the stock in order to take part in the split.
The split pay date - This is the day that the stock split takes effect and shareholders receive their new shares.
The split ex date  - This is the day that the stock will trade at the new adjusted split price.