The 2015 Chinese Stock Market Crash

How a speculative bubble fueled heavily by margin trading in Chinese stocks collapsed in mid-2015, prompting large-scale government intervention.

In mid-2015, China’s major stock markets, including the Shanghai Composite, experienced a dramatic stock market crash after a rapid run-up in prices over the preceding year. Chinese stocks had roughly doubled or more in value in the twelve months before the crash, driven substantially by millions of individual retail investors entering the market, many for the first time - and when the decline began, it unwound a large share of those gains within a matter of weeks.

A boom built partly on borrowed money

A significant driver of the 2015 run-up was margin trading: buying stocks partly with borrowed money, using the stocks themselves as collateral for the loan. Margin trading can amplify gains during a rising market, since an investor controls more shares than their own cash alone would allow. Regulatory changes in China had made margin trading more accessible in the years leading up to 2015, and a large wave of new retail investors, some with relatively little investing experience, took advantage of it.

Why borrowed money cuts both ways

Imagine an investor has $10,000 and borrows another $10,000 to buy $20,000 worth of stock. If the stock rises 20 percent, their $20,000 position is now worth $24,000 - a 40 percent gain on their original $10,000, since the loan amount stays fixed. But if the stock falls 20 percent instead, the position is worth $16,000, and after repaying the $10,000 loan, the investor is left with only $6,000 - a 40 percent loss on their original money. Margin trading doesn't just amplify gains; it amplifies losses by exactly the same mechanism, working in reverse.

The unwind

As prices began falling in June 2015, many margin investors faced what’s often called a margin call - a requirement to add more cash or sell shares to cover their loan as the value of their collateral dropped. Widespread forced selling to meet these margin calls pushed prices down further, which triggered more margin calls, in a downward spiral with some similarities to the automated-selling dynamics described in the 1987 Black Monday lesson elsewhere in this module, even though the underlying mechanism driving each was different.

Government intervention

Assuming government intervention in markets is unusual or automatically wrong

In response to the crash, Chinese authorities took a range of significant steps to try to stabilize prices, including suspending trading in a large share of listed companies, restricting large shareholders from selling, and having state-connected institutions purchase shares directly to support prices. This kind of large-scale **market intervention** was unusually direct compared to how many other major markets typically respond to a downturn, though governments and central banks worldwide do intervene in financial markets during periods of severe stress in various forms - the scale and directness of China's response in 2015 is what made it particularly notable, not the basic fact of intervening at all.

What it revealed

The crash drew attention to a feature of China’s stock market at the time: for much of the population, and for a meaningful share of company financing more broadly, the stock market was less deeply connected to the day-to-day real economy than in some other major economies, where corporate borrowing and household wealth are often more closely tied to stock valuations. This meant the crash, while dramatic for investors directly involved, had a more limited direct effect on China’s broader economic growth than a crash of similar size might have caused elsewhere - though economists continue to debate exactly how contained the wider economic effects genuinely were.

Key takeaways

Chinese stocks roughly doubled in the year before the 2015 crash, driven partly by new retail investors.
Margin trading amplified both the earlier gains and the eventual losses when prices reversed.
Forced selling to meet margin calls helped accelerate the decline once it began.
Chinese authorities responded with unusually direct and large-scale market intervention.
The crash highlighted how, at the time, China's stock market was less tightly linked to its real economy than in some other countries.