OMAHA, Neb. – Billionaire Warren Buffett says taking advice from Wall Street on deals is a bit like asking “the barber whether you need a haircut.” Buffett wrote in his annual letter to Berkshire Hathaway shareholders Saturday that investors should always be wary when taking advice from people who stand to profit from the transaction.

Buffett says the current Wall Street system of reviewing deals doesn’t always work well for investors because it almost always favors the deals CEOs propose. The 89-year-old CEO also says he remains optimistic about the future of his conglomerate because Berkshire’s managers and board members will protect the company after he and business partner Charlie Munger are gone.

READ MORE: Rural Mainstreet Index Remains Above Growth Neutral for Sixth Straight Month