According to CNBC, retail investors are borrowing more to buy stocks as total margin debt hit an all-time high of about $1.5 trillion in June, while Robinhood's margin book reached a record $21.6 billion in the second quarter, up 127% year over year and 332% from Q2 2024. The report centers on Hy Luu, a 29-year-old engineering consultant in Houston who said he has used margin to build a large Tesla position, including exercising $165,000 on five Tesla call options in June and buying 500 shares at $330 each, which pushed his borrowing above $156,000. Luu said his net worth has risen to more than $800,000 from negative territory seven years ago, but he also called the strategy risky and said he does not recommend it. The article said Robinhood's products are designed to appeal to a range of customers, while a spokesperson rejected the idea that its promotions specifically target margin traders. It also cited Fundstrat data showing that when monthly margin debt growth has exceeded 45% year over year since 1960, the stock market declined five out of six times.