Long-term investor Ron Barron’s mutual funds have been the biggest winners over the past five years, with huge gains. Barron Partners Fund ( BPTIX ), with more than $6 billion in assets under management, posted a five-year total annualized return of 25.7%, making it the top-performing U.S. equity fund over the period, according to MorningStar. . The fund focuses on US companies of any size with high growth potential. Elon Musk’s Tesla is the fund’s top holding, with a 52% portfolio weighting at the end of the third quarter. Baron was a long-time bull on Tesla. The investor said his firm has invested more than 15 times in Tesla since it first bought EV stock in 2014, Barron’s said at the annual Barron’s Investment Conference in New York earlier this month. Musk also spoke at the conference. Barron said at the conference that he believes that Tesla will be the largest company in the world in 10 years and that after ten years SpaceX will challenge him for that top spot. SpaceX previously disclosed that its largest acquisitions this year included $100 million in personal investments. Its second largest holding is CoStar Group, a provider of data and analytics for the commercial real estate sector. The company posted an 11.6% year-over-year revenue growth and a 12.4% net profit growth for the last quarter. The stock is up 2% this year, outperforming the broader market. According to a memo from Gordon Haskett last month, CoStar is “armed to the teeth” with great balance and cash for any future purchases. Acquired in 2019 is a relatively new holding, Barron Iridium Communications, a long-time provider of satellite communications to specialty phones. Iridium expects to finalize a direct-to-smartphone service deal with a smartphone partner later this year. Barron’s top holdings include insurance company Arch Capital Group, Charles Schwab, FactSet Research and Hyatt Hotels. The veteran investor said at a conference this month that his fundamental approach to investing involves finding companies with great leadership and competitive advantage. During this summer’s big market crash, when stocks plunged into a bear market on fears of a downturn, Barron’s told CNBC that investors are being given a once-in-a-lifetime buying opportunity.