In May, the volume of margin debt in the United States reached a new record level, indicating an increase in investor borrowing amid the ongoing rise in stock markets to new highs. Data published by FINRA showed that margin loan debt increased by $112 billion over the month, reaching a total of $1.42 trillion. This growth marked the second consecutive month of increase and pushed borrowing levels beyond previous peaks recorded during earlier market cycles. At the same time, the S&P 500 index rose by 5.1% in May, pushing market valuations and the level of investor leverage to historic highs. The latest data shows that over the past two months, the volume of investor borrowing increased by $195 billion. Compared with the same period last year, margin debt rose by $495 billion, an increase of 53.7%. Adjusted for inflation, margin debt increased by 7.9% compared with April and by 47.4% compared with May 2025.