Margin debt on the Fed's data: high vs GDP, low vs the market

Our read: on the Fed's quarterly data it isn't a record share of GDP (2.28%, below 2000's 2.64%), and it's low against the stock market (0.60%, 15th percentile) (our calc).

The Fed tracks margin lending (money brokers lend investors to buy stocks) every quarter. Z.1 is a quarterly balance-sheet measure that includes other receivables; its level isn't comparable to the monthly broker figure, so we use ratios and history only. Latest data: Q2 2026.

• Share of GDP: 2.28%. High, 6th of 146 quarters since 1990, but below the 2.64% peak in Q1 2000 (our calc).
• Share of the US stock market's value: 0.60%, the 15th percentile, far below the 1.71% high in Q3 2008 (our calc). Against the stocks it's borrowed against, it's low.
• Growth: +46.6% in a year, top tenth. That's the hot part.

Has fast growth meant trouble? After past top-tenth quarters, S&P 500 price returns (excl. dividends) over the next 12 months averaged +5.0%, counting each of 7 episodes once, with 5 of 7 positive. All quarters averaged +10.1% (our calc). Weaker than normal, not reliably negative.

Timing: on the Fed data, margin lending in dollars never peaked before the market in 2000, 2007 or 2021. Only the share of GDP did, by one quarter, in 2021.

What would prove us wrong

Set before publication. We report back in public when one trips.

• The share of GDP passes the Q1 2000 peak of 2.64%, checked at each Fed Z.1 release (next: Dec 10, 2026). Open · next check: Fed Z.1 release (Dec 10, 2026)
• The share of stock market value climbs back above its 1990–2026 median (0.93%, our calc) from 0.60%, checked at each quarterly Fed Z.1 release (next: Dec 10, 2026). Open · next check: Fed Z.1 release (Dec 10, 2026)
• The S&P 500 price return (excl. dividends) over the 12 months to Jun 30, 2027 is negative, which would make this episode the 3rd of 8 to be negative. Open · next check: 12 months to Jun 30, 2027

Method and sources

Figures marked "our calc" are our own arithmetic on the cited primary sources (company filings, earnings releases, public datasets). Every figure was checked against its source before publication.

Original post on X → Download data note

General research, the same for every reader. Not investment advice.