Fund guru Ron Baron says that he expects stocks to double over the next decade.

Baron told CNBC that current conditions will help businesses grow. “Now you’re at a very good level,” he said. “Interest rates are real low, energy costs are real low, housing is doing better, cars are — everything’s doing better.” He added that the big recent decline in oil prices is “hugely stimulative” and amounts to a 23 percent tax cut for Americans.

To double over a decade, stocks would have to average a 7.2% annual return.

Baron also talked broader strategy, saying that the key to picking good stocks for the long term is identifying a firm’s competitive advantage and understanding why other firms can’t do what it does. He also said it’s key to have a management team that can change with the times.

“Ultimately when other people do it, they have to make sure that the people who are running those businesses are fast enough on their feet and innovative enough in their thought processes to be able to make their businesses pivot and do something differently or take advantage of the opportunities,” he said.