As of April 2026, according to the latest FINRA data, U.S. stock margin debt has surpassed $1.3 trillion, hitting a historic high. In absolute terms, it’s in the 95%-100% historical percentile; in terms of margin debt/GDP, it’s in the 90%-95% percentile; and in terms of margin debt/total market cap, it’s in the 80%-90% percentile. This is considered a historically high leverage zone, though it hasn’t yet reached the extreme levels seen during the 2000 dot-com bubble. Year-over-year, margin debt has grown by over 50%, with a single-month increase exceeding $80 billion. This is already one of the fastest expansion rates in history. Based on experience, 0%-10% growth typically signals the early bull market stage, 10%-25% indicates the mid-bull stage, 25%-40% suggests the late bull stage, and anything above 40% points to a frenzy phase. Clearly, the market has now entered a high-heat zone. However, high heat doesn’t necessarily mean a peak. A dangerous signal usually comes when the year-over-year growth rate of margin debt turns negative. This indicates the market is starting to deleverage, either actively or passively. For the current AI cycle, the more critical factor is whether the AI infrastructure chain begins to cool down. After all, a fundamental-driven bull market is the real deal. nfa dyor