Under Buffett's direction, Berkshire Hathaway has never gone through a stock split. The Oracle of Omaha discourages stock splits since those splits increase short-term trading and can result in higher volatility. For instance, you need 100 shares of a company to trade a covered call. An investor would need roughly $60 million to trade a single covered call for Berkshire Hathaway class A (BRK.A).