Billionaire investor Ron Baron is standing by his bullish thesis on Tesla , seeing the Elon Musk-led electric vehicle maker growing as much as fivefold in the future. The Baron Capital chair and CEO revealed that his firm has made about 20 times its investment in Tesla since he first bought the stock in 2014. Tesla is the biggest holding in Baron's oldest and biggest fund, Baron Partners Fund (BPTIX), accounting for 46% of the portfolio. "I think Tesla in the next seven years will be about four or five times as big as it is right now in the stock market," Baron said Wednesday on CNBC's " Squawk Box ." "In the funds that I manage, I've been maxed out … when the stock went up 20 times. … As far as buying more, I would buy more if I could, but I can't." Baron is the rare active manager who has outperformed the market since the 1980s. The 80-year-old investor founded Baron Capital in 1982, and 16 of his 19 mutual funds representing 98.8% of the firm's assets under management have beaten their benchmark since inception. Baron Capital managed about $40 billion at the end of 2022. The investor said Tesla's car business can grow 30% in revenue this year and in 2024. Meanwhile, its battery business, which is $6 billion a year, could triple over the next three years. Baron is also bullish on SpaceX , Musk's private space company, saying he's one of the largest investors with 17.5 million shares worth more than $1 billion. "No company can compete because nobody can make these rockets go up and come down and land again," Baron said. "What is threatened here is cargo. They're going to have rockets to go from Nevada to Australia. You can move ordinance, you can move air freight, anything you want. Thirty-five minutes anywhere in the world." Baron said SpaceX is valued at $150 billion right now and has the potential to score a market capitalization of $500 billion to $600 billion. The Bucknell grad said he also has a small investment in Moderna , which is rallying early Wednesday on the back of a wide recommendation for the latest Covid vaccine from the Centers for Disease Control and Prevention. "What we thought was interesting is the opportunity that they were going to have all this cash coming in and they will do research to develop new drugs. That is what's happening now," Baron said.