When people lose money, everyone openly jokes about it—but would a truly profitable investor tell you? Let me introduce you to a fund: the Medallion Fund, established in 1988 by mathematician Professor Jim Simons, headquartered in a business park on Long Island, USA. From 1988 to 2018, its performance was astonishingly extraordinary: Pre-fee annualized return: 66%. After deducting a 5% management fee and 44% performance fee, the annualized return still stood at 39%. Over 30 years, it never had a single losing year. An investment of $100 in 1988 grew to nearly $400 million by 2018. The purple line in the chart below represents Medallion. Warren Buffett is the blue line; the S&P 500 is red. Their returns are on entirely different scales. But here’s the key point: since 1993, the fund has completely closed its doors to all external investors, allowing only employees and their families to invest. The fund’s size is capped at $15 billion; any excess profits are forcibly distributed among employees each year. For over three decades, outsiders have been unable to invest a single dollar. What about its performance since 2018? Unknown—they don’t disclose it. They don’t even have a Twitter account. Their website explicitly states: “We operate no other public websites besides https://t.co/43XKEvrd1I.” The most profitable fund in human history doesn’t tweet—and doesn’t accept outside capital. True alpha is never publicly shouted out, because alpha’s essence is information asymmetry; the moment it’s announced, it ceases to exist.