sourced story
1921-1929 (boom peak September 1929)Primary source · 2 sourcesWell documented

The Roaring Twenties Fuel a Stock Market Boom on Borrowed Money

The Dow rises sixfold in eight years as ordinary buyers borrow 90 cents of every dollar they put into stocks

On the timeline · around 1921-1929 (boom peak September 1929) · The Crash and CollapseThe Boom of the 1920sThe Crash and CollapseThe Roaring Twenties Fuel a Stock Market Boom on Borrowed Money192819291930

Quick facts

Dow, August 1921
63
Dow peak
381.17, September 3, 1929
Typical margin down payment
About 10 percent of the price
Fed response
Raised interest rates in 1928 and 1929 to limit speculation

What happened

The economic expansion of the 1920s reached its loudest on the New York Stock Exchange. The Dow Jones Industrial Average climbed from 63 in August 1921 to 381 by September 3, 1929, a sixfold rise in eight years. Automobiles, telephones, and radios spread through American homes, and a new industry of brokerage houses, investment trusts, and margin accounts let ordinary people buy shares with borrowed funds. A typical buyer put down about 10 percent of a stock's price and borrowed the rest, using the shares themselves as collateral. Borrowed money poured into the market and prices soared. In 1929 the economist Irving Fisher declared that stock prices had reached what looked like a permanently high plateau.

Why it matters

The speculative rise of the late 1920s left the market resting on a wall of debt. Because buyers had borrowed against the stocks they held, a fall in prices could force them to sell to cover their loans, which drove prices down further in a self-feeding spiral. That leverage turned an ordinary market correction into a collapse when confidence broke in October 1929, and it is one reason the Federal Reserve had spent 1928 and 1929 raising interest rates to try to cool the speculation.

How we know

Daily Dow Jones closing prices for 1920 through 1954 are preserved in Federal Reserve economic data, and the mechanics of margin buying are documented in the Federal Reserve History account of the 1929 crash drawing on the records of the Federal Reserve Board and reserve banks.

Sources

See something wrong? . Corrections with a source get fixed fastest.

Part of a timelineThe Great Depression20 events · The longest and deepest downturn in the history of the modern industrial economy, from a stock market that lost 89 percent of its value to breadlines that ran for a decadeView all →