Home » Share Market » What is Runoff?

What is Runoff?

The closing of the stock market often brings a flurry of last-minute trades as investors and traders try to get their final transactions in before the session ends. This rush of activity as the market wraps up for the day is known as “runoff.” But what exactly is runoff, and why does it matter in today’s stock exchanges?

Read on to gain a deeper understanding of this key concept and the crucial role it plays in ensuring transparent and orderly markets. We’ll explore the definition and history of runoff, look at specific examples of high-profile cases, and discuss why proper runoff procedures are vital for maintaining market integrity in the modern electronic trading era.

Defining runoff in the share market 

Runoff is a term used to describe trades that happen right before the stock market closes. During this time, investors rush to place their last orders to take advantage of price movements and prepare for the next day’s trading. This rush of activity can cause trading volume and prices to fluctuate significantly, making it hard to determine the actual market supply and demand.

In order to manage the situation when there is a sudden increase in trading at the end of the day, there are some specific rules and procedures in place known as “runoff procedures.” These procedures help to keep things fair and transparent in the market. They provide a clear process for handling the increased activity so that everyone involved knows what to expect and can make informed decisions.

Understanding the timeline and reporting process

While the exact protocols vary between exchanges, runoff generally works on the following timeline:

  • 4:00 PM – The closing bell marks the official end of regular trading for the day. However, the market does not instantly shut down. 
  • 4:00-4:05/4:10 PM – A runoff period continues as orders are matched up. Timeframes range from a few minutes up to 15 minutes, depending on the exchange. These additional minutes accommodate stragglers and prevent panic selling.
  • Overnight – Trade details and reports from the runoff session are finalised, verified, and reconciled by exchange officials. 
  • Next trading morning- Closing prices, indexes, and volumes are officially disseminated to the public at the opening of the market. 

This reporting structure creates accountability around the runoff process. By formally logging and confirming all trade details before public release, investors gain confidence in the accuracy of the numbers. It reduces uncertainty around potentially erroneous or misleading transactions as everything is carefully double-checked.

Evolution from paper ticker tapes

It is important to have a system that keeps track of all the buying and selling of stocks after the markets close for the day. This system is called “runoff,” and it has been around since the early 1900s, back when stocks were traded using paper records. 

At the end of each trading day, the stocks’ prices were written down on long strips of paper called “ticker tapes.” These tapes kept running even after the markets closed, recording any transactions that happened during the runoff period. 

To make sense of all this information, traders would gather up the ticker tapes and manually compile the data overnight. The next morning, they would report everything that happened during the runoff period. 

Even though technology has advanced a lot since then, the purpose of runoff remains the same – to create a clear record of all the buying and selling that happens after the markets close so that investors can be confident that everything is happening transparently.

Examples demonstrating the need for proper controls  

Over the last ten years, electronic trading platforms have become more advanced, and transactions are now completed much faster using automation. This has also led to the emergence of high-frequency trading (HFT) and complex algorithms. As a result, it has become more important than ever to have a well-organised and structured process to avoid any chaos during a market crisis

Let’s take a look at some real-life examples that show what can happen when this process is not followed properly:

  • 2010 Flash Crash: In one of the most well-known market disruptions, the Dow Jones tanked over 600 points in 5 minutes before swiftly recovering most of the losses 20 minutes later. While multiple factors contributed to the crash, the SEC later determined that faulty runoff procedures helped fuel the crisis. 
  • 2012 Knight Capital Group Debacle: In a well-known incident, a computer program designed to trade stocks experienced a malfunction just as the market was closing for the day. This caused the program to send out a large number of incorrect orders to different stock exchanges, resulting in a loss for the company behind the program. This event drew attention to the potential risks that technological errors can pose in our highly automated financial landscape.

Executing runoff best practices for modern markets

These examples underscore why proper runoff protocols are integral, especially given current market complexities. Here are some best practices for exchanges:

  • Extend trading hours 5-15 minutes past the closing bell to facilitate orderly finishes.
  • Perform test runs for software to uncover potential bugs before live deployment. 
  • Implement “speed bumps” – intentional millisecond delays to prevent cascading reactions.
  • Kill switch mechanisms are required to halt trading if necessary.
  • Institute additional checks and balances and report on out-of-hours transactions.

The need for cooperation between exchanges and regulators

Maintaining fair and stable markets requires collaboration between exchanges and market oversight entities. Regulators play a key role in enforcing strict governance around runoffs by:

  • Setting policies – Regulators should continually assess and update standards to align with innovations.
  • Performing reviews – Regular audits of exchange protocols help verify proper procedures are in place.  
  • Coordinating efforts – Communication between different exchanges and governing bodies enables coordination.
  • Enforcing transparency – Strict reporting rules and consolidation of runoff data promote access and trust.

Likewise, exchanges must prioritise investing in robust technological infrastructure and risk management systems. 

By working together, regulators and exchanges can ensure efficiency and stability as market mechanics rapidly advance.

The ongoing quest to balance speed and security   

The way financial markets work today is fast-paced, which has its advantages but also presents challenges. Quick transactions can make it easier for traders to buy and sell assets, which is good for everyone. However, if things go wrong, it can cause serious problems in just seconds, as we’ve seen in the past.

This is why it’s important to have good policies in place to manage these situations. Exchanges need to make sure that they can close transactions in an orderly way while still being able to handle lots of orders quickly so that they can stay competitive. At the same time, regulators must ensure that new financial technologies are safe and reliable.

There are no easy solutions to these challenges, but by working together, the industry can make progress without taking on too much risk. This means that we need to be careful and responsible in managing financial transactions rather than just trying to ban new technologies altogether.

By continuously improving how we do things and ensuring that we have good rules in place, we can keep the financial system stable and reliable, even as things continue to move quickly.


Closing auctions play a pivotal role in the world’s exchanges. They set opening prices for the next day’s trading. Establishing order is crucial, and runoff promotes transparency in the midst of chaos. However, keeping up with rapidly advancing technologies presents complex challenges. Regulators and exchanges can work together to maintain market integrity. Runoff represents the industry’s legacy of adapting to support orderly markets, no matter the conditions.


What exactly is runoff in the stock market?

Runoff refers to the flood of last-second trades that pour in the right as the market closes each day. It’s a frenzy of activity from investors trying to sneak in final transactions before the trading session ends.

How does runoff trading get reported to the public?

The details of all runoff activity are logged, verified, and consolidated overnight by exchange officials before being officially released when the market reopens the next day. This structured process promotes transparency.

Why is runoff so important in today’s high-speed markets?

With computerised trading dominating activity, markets can experience huge, destabilising swings in seconds. Proper runoff governance curbs this volatility at the close by implementing speed bumps, kill switches, and other protective measures.

How has technology changed runoff practices over time?

It evolved from a manual process with paper ticker tapes to today’s electronic platforms. However, the core purpose remains the same: to record closing figures and ensure accuracy before central public dissemination.

Who helps oversee the runoff process besides the exchanges?

Financial regulators play a crucial role by coordinating efforts between exchanges, enforcing strict runoff policy standards, performing periodic audits, and promoting overall transparency.

Enjoyed reading this? Share it with your friends.

Post navigation

Leave a Comment

Leave a Reply

Your email address will not be published. Required fields are marked *