Black Monday and Market Crashes

Black Monday and Market Crashes

8 Min.


On October 19th, 1987, the financial world witnessed an event that would be forever etched in history as Black Monday. This notorious day marked a sudden and severe stock market crash, characterized by a dramatic decline in the Dow Jones Industrial Average (DJIA), a renowned index that gauges the performance of the US stock market. Plummeting by over 22%, the DJIA experienced this devastating blow after enduring two significant drops just a week earlier.

Black Monday's repercussions reverberated globally, signaling the onset of a worldwide decline in stock markets. This fateful day holds an infamous position in the annals of financial history, serving as a stark reminder of the inherent volatility and vulnerability of these markets.

The sheer magnitude of the crash was exemplified by the overwhelming trading volume witnessed on exchanges. Such was the deluge of activity that the computers of that era were ill-equipped to handle the sudden surge, leaving orders unfilled for hours and impeding the timely transfer of substantial funds.

Unsurprisingly, a significant crash of this nature inevitably reverberated across the futures and options markets. Its impact extended far beyond the borders of the United States, profoundly affecting global markets. By the end of the same month, most major indexes worldwide had experienced precipitous declines ranging from 20% to 30%.

While the term "Black Monday" predominantly references the 1987 crash, it has also come to encompass other cataclysmic market crashes that have unfolded since then. This terminology is a stark reminder of the dire consequences that can accompany such profound disruptions in the financial realm.

What Causes Market Crashes? 

The causes behind stock market crashes are typically multifaceted, defying a single attribution. Curiously, the 1987 Black Monday crash transpired without any major preceding news event. Instead, it was the convergence of various factors that, when combined, engendered an atmosphere characterized by panic and uncertainty. So, what were these influential factors?

First and foremost was the advent of computerized trading systems. In the past, stock markets embodied bustling and crowded arenas where traders directly exchanged assets on the trading floor of the exchange. However, throughout the 1980s, there was a significant shift toward reliance on computer software to facilitate trading activities. This transition ushered in a new era of accelerated trading, with systems capable of executing thousands of orders in seconds. Consequently, these advancements amplified the velocity of substantial price fluctuations. Today, the introduction of trading bots has taken this velocity to unprecedented levels, enabling trillions of dollars in value to be swiftly moved within seconds of an unforeseen news event.

Additional factors, such as the United States trade deficit, international tensions, and various geopolitical circumstances, have also been implicated as underlying causes. Furthermore, the expanding influence of the media exacerbated the impact and severity of the event.

Nevertheless, it is important to acknowledge that while these factors may have played a role in precipitating the crash, ultimately, it was human decision-making that shaped its course. Market psychology assumes a prominent role in instances of widespread sell-offs, often driven by mass panic.

What Is a Circuit Breaker? 

In the wake of the events that transpired during Black Monday, the US Securities and Exchange Commission (SEC) swiftly implemented a range of measures aimed at averting or, at the very least, mitigating similar occurrences in the future. One of these regulatory measures, known as a circuit breaker, acts as a safeguard by halting trading when certain predetermined percentage thresholds are breached in relation to the daily opening price. Although our primary focus is on the United States, it is worth noting that circuit breakers have been adopted in numerous other markets as well.

Circuit breakers are applicable to major indexes such as the Dow Jones Industrial Average (DJIA) or the S&P 500, as well as individual securities. Now, let's delve into the operational mechanics of these circuit breakers. When the S&P 500 experiences a decline exceeding 7% within a single trading day, a Level 1 circuit breaker is triggered, pausing trading for a period of 15 minutes. Once this brief hiatus concludes, trading recommences. However, should the market continue to decline, eventually reaching a 13% loss from the daily open, a Level 2 circuit breaker comes into effect. Again, a 15-minute trading halt ensues, providing a temporary reprieve. Finally, if the market endures a steep plunge resulting in a 20% loss from the market open, the Level 3 circuit breaker is enacted. In this scenario, trading is halted for the remainder of the day, allowing market participants to regroup and reassess the situation.

The implementation of circuit breakers serves as a critical mechanism in safeguarding market stability and curtailing the potential for catastrophic downturns. By imposing temporary pauses in trading during periods of heightened volatility, these measures provide an opportunity for market participants to absorb information, make informed decisions, and help mitigate the severity of potential market disruptions.

Pros and Cons of Circuit Breakers

The utilization of circuit breakers has sparked both support and opposition, with proponents highlighting their efficacy in averting sudden market downturns while critics raise concerns about their impact.

Detractors contend that circuit breakers can harm markets, exacerbating the severity of crashes. This argument stems from the fact that these predetermined percentage thresholds, being publicly known, may influence order placement and artificially reduce liquidity levels within the order book at specific price points. The reduction in liquidity can potentially amplify volatility, as there might not be sufficient orders to absorb an unexpected surge in supply. Critics assert that markets would be more likely to naturally reach a state of equilibrium without circuit breakers impinging on liquidity areas.

In the context of global market indexes like the S&P 500, it is worth noting that circuit breakers are only triggered in response to downward movements. Conversely, for individual securities, circuit breakers can be activated in the event of both upward and downward price movements.

Effective Strategies for Preparing for Market Crashes

Inevitably, market crashes are an inherent aspect of market dynamics and crowd psychology. However, taking proactive steps to prepare for such downturns can help mitigate their impact. So, how can one navigate the potential perils of a market crash?

First and foremost, it is crucial to establish a well-defined investment plan or comprehensive trading strategy. During a market crash, when panic selling ensues among many investors, it is paramount to maintain a sense of calm and rationality and avoid making emotionally-driven decisions. A long-term investment plan or trading strategy is a guiding framework that discourages impulsive actions.

Additionally, implementing a stop-loss strategy is imperative. Protecting the downside is essential for traders engaged in shorter-term trades, but interestingly, it is a practice that is surprisingly less common among long-term investors. Even if a stop-loss order allows for larger price fluctuations, it can safeguard against substantial losses in a devastating market crash.

It is worth noting that historical evidence reveals global market crashes to be temporary occurrences. While periods of economic recession may extend over multiple years, markets have consistently tended to recover in due course. By zooming out and observing the broader trajectory, it becomes evident that the global economy has consistently demonstrated growth over centuries, with these corrections serving as temporary setbacks.

However, it is essential to recognize that this observation does not necessarily apply to cryptocurrency markets. The blockchain industry and cryptocurrencies, as a volatile asset class, carry inherent risks. Consequently, severe market crashes may have long-lasting ramifications, and some cryptoassets may never regain their previous value after such tumultuous events.

Other notable Black Mondays 

October 28th, 1929

Crashing stock markets in the 1930s preceded the Great Depression. The 1929 stock market crash ranks as the worst one to date when looking at its long-term consequences on the economy.

September 29th, 2008

Stock markets began to decline once the US housing bubble broke. This ultimately caused the Great Recession in the late 2000s and early 2010s. 

March 9th, 2020

The coronavirus outbreak and an oil price war caused the US stock market's worst day since the Great Recession. It had been the most significant one-day decline since 2008 at the time. 

March 16th, 2020

Increasing concerns were expressed about the coronavirus pandemic's possible economic impacts. As a result, the US market fell more than one day than it did during the meltdown a week earlier. This day may be regarded as the apex of the initial shock caused by the coronavirus's impact on the stock market.


Black Monday in 1987 remains etched in history as a significant and severe market crash. Interestingly, the term "Black Monday" is not exclusive to this event but is also employed to describe other notable stock market crashes, including those of 1929, 2008, and 2020.

In response to the impact of Black Monday, regulatory measures were introduced to address the risks associated with sudden stock market downturns. The circuit breaker stands out as a highly influential and contentious mechanism among these measures. Circuit breakers aim to mitigate the effects of market flash crashes by halting trading when predefined percentage loss thresholds are reached.

To prepare for the inevitable occurrence of market crashes, it is prudent to consider various scenarios and devise a robust investment plan or trading strategy. Emphasizing risk management, portfolio diversification, and understanding market psychology can serve as essential components to shield against significant losses during market crashes. By adopting these measures, investors can navigate turbulent times more effectively.

Black Monday
Circuit Breakers
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