Difference Between Open Interest and Volume

A guide explaining the two metric and how they influence the decision-making of traders.
Difference Between Open Interest and Volume
3 mins
6 October 2023

Those who invest in the financial market need to be patient, put in the hard work, and grasp the nuances. You must have the right tools at your disposal and thoroughly research and analyse your options. It is almost impossible to predict market movements, and as such, even the smallest of indicators can be vital.

The two widely used metrics while analysing the market are open interest and volume. These two indicators help traders and investors assess the market flow and sentiment relating to futures and options contract trading. Comprehending these two concepts is paramount, as they help traders speculate market movements, price direction, and market liquidity.

What is open interest?

Open interest alludes to the total number of outstanding contracts for a certain financial instrument, such as futures or options, that have not yet been settled. It refers to the total number of positions actively held by traders in the market and is used as a measure of market liquidity and activity. Open interest, similar to other securities, is prone to market movements.

Intuitively, open interest increases when new contracts are opened. This implies that for a specific security, there are a greater number of buyers and sellers. On the flip side, when positions in the current contracts are closed out by buyers and sellers, the open interest decreases. This indicates that the investors are not interested in opening new positions.

Let us look at an example to understand this better.

Example:

  • Let us suppose that open interest of the XYZ call option is 0 on the first day.
  • Investor ‘A’ purchases 20 XYZ options contracts as a new position on the second day, and the open interest for this specific call option is 20.
  • The day after, 15 XYZ contracts were closed, and 20 were opened. This implies that the open interest increased to 25.

Why does open interest matter in trading? 

Open interest matters in trading because it serves as a crucial indicator of market liquidity and activity for a security. When open interest increases, it signals the creation of new contracts and an expanding market, indicating a higher number of buyers and sellers. This implies greater liquidity and ease of trading due to the influx of participants and capital. Conversely, declining open interest suggests that market participants are not initiating new positions and are closing existing ones, leading to reduced market activity. In such cases, the market is drying up, making it less ideal for trading opportunities. Traders often use open interest as part of their analysis to gauge the health and attractiveness of a market, helping them make informed decisions about when and where to invest or trade.

What is trading volume?

To understand the difference between open interest and volume, you must also understand the concept of volume trading. Volume records the quantum of options or futures contracts swapped between buyers and sellers on any given trading day. It's quantified down to individual transactions, encompassing all the futures and options contracts traded between buyers and sellers for that specific security.

Thus, each and every transaction is considered for calculating the daily volume. It helps traders assess the market activity, liquidity, and potential trends of a particular security. Higher volume often indicates a strong market interest and potential price movements. However, a security that isn’t being actively traded indicates low trading volume. These figures are tracked by the market exchange and are updated constantly, with the final daily trading volume computed towards the end of the trading day.

Let us consider the following example.

Example:

  • Let us suppose the volume in call option ‘XYZ’ with a strike price of Rs. 60 and an expiration date of around 2 weeks did not trade any contracts in the first session. In such a scenario, the trading volume is 0.
  • In the second session, if an investor ‘A’ buys 10 call option contracts and no other trade occurs during the day, the trading volume will be 10.

We’ve understood the meanings of open interest and volume. Let us now take a look at their differences.

Additional read: What is Intraday Options Trading

Why does volume matter in trading?

Volume is a crucial factor in trading because it serves as a direct indicator of a security's market activity and liquidity. High trading volumes signal active interest in a security, indicating opportunities for more efficient order execution. Traders often focus on a security's average daily trading volume to gauge market dynamics. For example, when a security experiences higher-than-usual trading volume alongside a price change, it can suggest a favorable opportunity. Thus, trading volume helps validate the significance of price movements and direction. It provides traders with valuable insights into the strength and sustainability of market trends and aids in making informed decisions about when to buy or sell a security.

Open interest vs. volume

Before we compare and contrast the two metrics, it is essential to remember that they are important in distinct ways. Open interest and volume are important indicators of market activity and liquidity.

  • Open interest represents the quantum of futures and options contracts that are unsettled or active for an asset at any point in time. Meanwhile, volume pertains to particular securities traded within a specified timeframe.
  • Let us consider an example. Trader ‘A’ holds 15 option contracts and sells them to trader ‘B’, who just entered the market. Here, there is no change in the open interest as the positions were transferred and not opened or closed. However, trading volume increased by 15 because of this transfer.
  • Open interest is extremely volatile and is subject to increases and decreases. It paints a comprehensive picture of the interest in a specific security. On the other hand, volume quantifies the trade for a particular period and certain security.
  • Another significant difference between open interest and volume pertains to the frequency with which the data is updated. As previously mentioned, the aggregate volume is tracked and computed by the market exchange towards the end of every trading day. However, open interest values are not updated frequently.

Conclusion

Open interest and volume are essential metrics that can influence and impact the decision-making process of traders. Coming to the open interest vs. volume comparison, they are different yet important. They help traders identify opportunities by gauging market activity, liquidity, and sentiment, along with potential entry and exit points.

Disclaimer

1. Bajaj Finance Limited (“BFL”) is a Non-Banking Finance Company (NBFC) and Prepaid Payment Instrument Issuer offering financial services viz., loans, deposits, Bajaj Pay Wallet, Bajaj Pay UPI, bill payments and third-party wealth management products. The details mentioned in the respective product/ service document shall prevail in case of any inconsistency with respect to the information referring to BFL products and services on this page.

2. All other information, such as, the images, facts, statistics etc. (“information”) that are in addition to the details mentioned in the BFL’s product/ service document and which are being displayed on this page only depicts the summary of the information sourced from the public domain. The said information is neither owned by BFL nor it is to the exclusive knowledge of BFL. There may be inadvertent inaccuracies or typographical errors or delays in updating the said information. Hence, users are advised to independently exercise diligence by verifying complete information, including by consulting experts, if any. Users shall be the sole owner of the decision taken, if any, about suitability of the same.

Standard Disclaimer

Investments in the securities market are subject to market risk, read all related documents carefully before investing.

Research Disclaimer

Broking services offered by Bajaj Financial Securities Limited (BFSL) | Registered Office: Bajaj Auto Limited Complex , Mumbai –Pune Road Akurdi Pune 411035 | Corporate Office: Bajaj Financial Securities Ltd,1st Floor, Mantri IT Park, Tower B, Unit No 9 & 10, Viman Nagar, Pune, Maharashtra 411014| CIN: U67120PN2010PLC136026| SEBI Registration No.: INZ000218931 | BSE Cash/F&O (Member ID: 6706) | DP registration No : IN-DP-418-2019 | CDSL DP No.: 12088600 | NSDL DP No. IN304300 | AMFI Registration No.: ARN – 163403|

Research Services are offered by Bajaj Financial Securities Limited (BFSL) as Research Analyst under SEBI Regn: INH000010043. Kindly refer to www.bajajfinservsecurities.in for detailed disclaimer and risk factors

This content is for educational purpose only.

Details of Compliance Officer: Ms. Kanti Pal (For Broking/DP/Research)|Email: compliance_sec@bajajfinserv.in/Compliance_dp@bajajfinserv.in |Contact No.: 020-4857 4486 |

Investment in the securities involves risks, investor should consult his own advisors/consultant to determine the merits and risks of investment.

Frequently asked questions

What is better open interest or volume?

Open interest and volume serve different purposes. Open interest measures the number of outstanding contracts in the futures or options market, indicating market participation and potential for liquidity. Volume reflects the total number of shares or contracts traded in a specific time period, offering insights into immediate market activity. Which one is "better" depends on your trading strategy; open interest is more about the potential for future trading, while volume is about current activity.

What does it mean when volume is greater than open interest?

When volume is greater than open interest, it means that a high number of contracts or shares are actively being traded in the market, reflecting intense current interest and activity. This typically occurs in intraday trading and can be a sign of short-term price volatility.

What does high open interest but low volume mean?

High open interest but low volume indicates that there are many open contracts, but few are actively being traded. This suggests a lack of recent interest in the security, which may lead reduced liquidity.

How does open interest affect stock price?

Open interest itself doesn't directly affect stock prices. Instead, it reflects the number of outstanding contracts. However, changes in open interest can indirectly influence prices as they may indicate shifts in market sentiment. For instance, a significant increase in open interest could signal a bullish or bearish trend, potentially impacting stock prices as traders adjust their positions.

Show More Show Less