A stock market fall can occur as a result of a large disastrous event, an economic crisis, or the bursting of a long-term speculative bubble. Reactionary public fear in response to a stock market fall can also be a key cause, prompting panic selling that further depresses prices.
- A stock market crash is a sudden or severe drop in overall share prices, usually within a day.
- Stock market crashes can be due to economic or natural disasters, speculation, or investor panic.
- Investors can prepare for stock market crashes by diversifying portfolios and shifting to CDs or bonds.
The stock market is constantly moving, with prices of individual equities rising and falling throughout the trading day. Whenever the majority of them or a representative group of them, called a stock market index takes an especially large dive, a panicked cry often arises: “The stock market has crashed!”
Stock market crashes are certainly scary. Equities across the board decline in value. Investors lose enormous sums of money on paper, anyway. But what causes them? And what are the aftereffects?
Here is a closer look at what a stock market crash is and what you need to know before one impacts your portfolio.
What causes a stock market crash?
Historically, stock market crashes often occur after a long period of economic and market growth. Confidence in the economy, steady stock gains, and low unemployment are all drivers of bull markets, as these sustained rallies are known. As more and more stocks are purchased, prices go up both for individual equities and the stock indexes themselves.
But in the world of securities, prices can’t keep rising indefinitely, and bull markets can only last for so long. Sometimes it’s a general shift in sentiment, as in 1929, but usually, some precipitating event occurs.
Numerous things can cause a stock market to crash, including:
- Panic: This is one of the most common contributing factors to a crash. Stockholders who fear the value of their investments are in danger of dropping will sell their shares to protect their money. As prices begin to drop, the fear spreads, more sales ensue, and this can lead to a crash. Anything from a major player in the market having financial trouble to fears about the impact specific legislation may have can cause scores of investors to panic and sell off stock.
- Natural or man-made disasters: These can include all sorts of catastrophes, from floods to wars to pandemics. Case in point: the coronavirus-induced crash of March 2020. As the realization of the spread of COVID-19 began to take hold, the economic outlook for the US and countries worldwide began to look grim. While countries announced travel limitations, mandatory business shutdowns, and quarantines, consumers stocked up on essential supplies causing shortages, companies began protecting profit margins through layoffs and furloughs, and investors started selling off stocks.
- Excessive leverage: When things are going well, leverage (a.k.a. “borrowed money”) can seem like an excellent tool. For example, if I buy 1,00,000 worth of stock and it rises by 20%, I made 20,000. If I borrow an additional 1,00,000 and bought 2,00,000 worth of the same stock, I’d make 40,000 doubling my profits.
On the other hand, when things move against you, leverage can be downright dangerous. Let’s say that my same 1,00,000 stock investment dropped by 50%. It would sting, but I’d still have 50,000. If I had borrowed an additional 1,00,000, a 50% drop would wipe me out completely.
Excessive leverage can create a downward spiral in stocks when things turn sour. As prices drop, firms and investors with lots of leverage are forced to sell, which in turn drives prices down even further. The most notable occasion was the Crash of 1929, in which excessive purchasing of stocks on margin played a major role.
- Interest rates and inflation: Generally speaking, rising interest rates are a negative catalyst for stocks and the economy in general.
This is especially true for income-focused stocks, such as real estate investment trusts (REITs). Investors buy these stocks specifically for their dividend yields, and rising market interest rates put downward pressure on these stocks. As a simplified illustration, if a 10-year Treasury note yields 3% and a certain REIT yields 5%, it may seem worth the extra risk to income-seeking investors to choose the REIT.
On the other hand, if the 10-year Treasury’s yield spikes to 4%, the REIT’s dividend will (roughly) need to rise proportionally to attract investors. And lower stock prices translate to higher dividend yields, on a percentage basis.
From an economic standpoint, higher interest rates mean higher borrowing costs, which tends to slow down purchasing activity, which can in turn cause stocks to dive. So, if the 30-year mortgage rate were to spike to, say, 6%, it could dramatically slow down the housing market and cause homebuilder stocks to take a hit.
- Political risks: While nobody has a crystal ball that can predict the future, it’s a safe bet that the stock market wouldn’t like it much if the U.S. went to war with, say, North Korea.
Markets like stability and wars, and political risk represent the exact opposite. For instance, the Dow Jones Industrial Average dropped by more than 7% during the first trading session following the Sept. 11, 2001, terror attacks, as the uncertainty surrounding the attacks and the next moves spooked investors.
- Tax changes: The recent Tax Cuts and Jobs Act should certainly have the effect of higher corporate earnings and is likely to be a generally positive catalyst for the market.
On the other hand, tax increases can have the opposite effect. One potential way to fix the Social Security funding problem would be to raise payroll taxes on employees and employers. There are several ways this could happen, but this would mean lower paychecks for workers and higher expenses for employers, and could certainly be a negative catalyst.
The same could be said if short-term capital gains taxes or dividends lose their favorable treatment, if the corporate income tax is raised in the future, or if any other significant tax hikes occur. This isn’t likely to happen while the Republican Party is in power, but it’s certainly possible in the future.
- Economic crises: A problem in industry or one section of the economy often has a ripple effect. One example is the subprime mortgage crisis of 2007-2008. Earlier in the decade, deregulation in the banking industry had led to an increase in mortgages to high-risk borrowers. When these borrowers began defaulting on payments, home prices dropped, and the housing market collapsed. Many of the now-worthless mortgages had been packaged and sold off to institutional investors who in turn lost billions. Big firms began to fold, and from Sept. 19 to Oct. 10, the Dow Jones Industrial Index declined 3,600 points.
- Speculation: When you have people and companies investing in a sector in the hopes that an asset or security will grow or based on future performance expectations, you have speculation that often creates a bubble. If the performance disappoints, and the hype doesn’t live up to reality, the bubble bursts, and a mass sell-off occurs.
What happens when a stock market crashes?
There are many definitions of what a stock market crash is. Some categorize a crash strictly as a stock market or a stock market index (a representative sampling of stocks) losing more than 10% of its value in a single day. Others provide a more general view, simply stating that a crash is a significant or dramatic loss in the stock market’s value, and the prices of shares overall, usually within a short period.
Any way you look at it, a stock market crash happens when confidence and value placed in publicly traded assets go down, causing investors to sell their positions, and move away from active investing, and toward keeping their money in cash, or the equivalent.
The impact of a crash can vary as well. Sometimes, it’s limited. For example, on Oct. 19, 1987, after five years in a strong bull market, the Dow Jones Industrial Average (DJIA) and S&P 500 both dropped more than 20%, following markets throughout Asia and across Europe. The crash was short and markets quickly recovered. Within a few days, the DJIA regained more than 43% of the points it lost and within nearly two years the market had recovered almost 100%.
At other times, the effects are widespread and longer-lasting. The most notorious example is the Crash of 1929. Stock prices dropped first on Oct. 24th, briefly rallied, and then went into free fall on Oct. 28-29. Ultimately, the market lost 85% of its value. Though not the sole cause, this crash was one of the contributing factors to the Great Depression, the worst economic period in American history, lasting nearly 10 years.






































