US margin debt rose $26 billion in September to $1.48 trillion, second highest on record

Margin debt rose $26 billion in September to $1.48 trillion, the second-highest level on record. Since the start of 2026, margin debt has surged $255 billion, or 21%. As a share of GDP, it reached a record 4.5%, surpassing the 2021 peak of 3.6%. The margin debt-to-M2 ratio hit 6.3%, the third-highest on record, near the dot-com bubble peak of 6.4%.