Amazon, Apple, Google and Tesla have all done it. Here’s why companies split their stock

Google is just one of dozens of companies recently making its stock more affordable. The tech giant’s parent company, Alphabet (GOOGL), split its two classes of shares (GOOG) by a 20-to1 ratio in July.

Amazon (AMZN) made the same 20-for-1 move in June while Tesla (TSLA) announced around the same time that it’s going with a 3-for-1 stock split. Apple (AAPL) has split its stock five times since the company went public.

Watch this video as CNBC’s Emily Lorsch explains what a stock split is and why companies do it.