The New York Stock Exchange publishes end-of-month data for margin debt on the NYXdata website, where we can also find historical data back to 1959. Let’s examine the numbers and study the relationship between margin debt and the market, using the S&P 500 as the surrogate for the latter.
The first chart shows the two series in real terms — adjusted for inflation to today’s dollar using the Consumer Price Index as the deflator. I picked 1995 as an arbitrary start date. We were well into the Boomer Bull Market that began in 1982 and approaching the start of the Tech Bubble that shaped investor sentiment during the second half of the decade. The astonishing surge in leverage in late 1999 peaked in March 2000, the same month that the S&P 500 hit its all-time daily high, although the highest monthly close for that year was five months later in August. A similar surge began in 2006, peaking in July, 2007, three months before the market peak.
In real (inflation-adjusted) terms, the latest margin debt is at an interim high, 3.5% below the all-time high in July 2007.