Overview 

The additional surveillance measure (ASM) is a framework implemented by the stock exchanges under SEBI’s regulatory framework to monitor securities showing unusual price movements, volatility or trading patterns. Depending on the track and stage, a stock on the ASM list stock market participants may face higher margins, tighter price bands or changed settlement conditions. Inclusion is a surveillance action, not proof of fraud or weak fundamentals. This guide explains the ASM framework NSE applies, how short-term and long-term ASM differ, how to check the latest lists and what to review before placing an order.

What is ASM in the Stock Market?

Definition of ASM (Additional Surveillance Measure)

ASM stands for additional surveillance measure, a framework implemented by the exchanges under SEBI’s regulatory framework. Securities that show sharp price moves, concentrated client activity or other unusual behaviour are shortlisted and placed in stages, each with specific trading conditions. Placement reflects surveillance criteria and is not an adverse finding against the company.

Purpose and importance in stock trading

ASM is a pre-emptive surveillance framework. It aims to flag securities showing unusual market behaviour, make speculative positions costlier and encourage additional due diligence by participants before they trade.

Why is ASM Important for Traders and Investors?

Enhancing market integrity

Stocks that rise or fall sharply with few participants can distort price discovery. Higher margins and tighter bands make it harder for a small group of clients to move a price, which supports fair and orderly markets.

Protecting investors from high-risk stocks

A stock on the ASM list signals elevated risk to those who might otherwise chase a rally. The flag does not mean the company is weak or that its price will fall. It indicates unusual trading behaviour that deserves research before any decision.

How Does the ASM List Work?

Criteria for inclusion in the ASM list

The framework has two tracks, and the criteria differ between them and across securities (mainboard, SME and those with derivatives). The factors monitored include price variation adjusted for the market index, concentration among the top 25 clients, market capitalisation, volume variation, delivery percentage and the number of unique PANs, among others. The table gives a simplified view for mainboard equity.

Track	What is screened	Illustrative conditions
Short-term ASM	Price movement over days, adjusted for the Nifty, with client concentration or unique PAN tests	For example, a close-to-close move of 25% or more beyond the index-adjusted level over five trading days, together with top-25 client concentration of 30% or more
Long-term ASM	Price variation over months, adjusted for the index, with concentration and market capitalisation tests	Several separate criteria, with top-25 client concentration of 25% or more and market capitalisation limits that vary by criterion

These are examples, not a single universal entry rule. Stocks already under the Graded Surveillance Measure or trade-for-trade are excluded from short-term ASM. The applicable circular sets the exact thresholds.

Process of monitoring and review

Exchanges screen securities against the criteria and publish additions through circulars and dashboards. 

For mainboard short-term ASM, a stock is retained in a stage for a minimum of 5 or 15 trading days, and review begins from the sixth or sixteenth trading day. SME securities follow their own provisions in the applicable circular. 

Long-term ASM is reviewed stage-wise on a weekly basis, and a stock must complete 90 calendar days before it becomes eligible to exit. Eligibility for review does not guarantee removal, and exits are stepwise from one stage to the next lower one.

What Are the Key Features of the ASM List?

Types of stocks categorised

The ASM framework NSE uses covers mainboard equity, SME stocks, PSU companies and stocks with equity derivatives. The long-term and short-term tracks apply in different ways to each category, so restrictions are not identical across them. Stocks under other surveillance frameworks are handled separately.

Duration of ASM measures

Measures are not permanent. 

• Short-term stages continue only while the criteria hold after the minimum retention period.
• Long-term placement carries a 90-calendar-day minimum before exit eligibility, and a stock can remain longer or move up a stage if the behaviour persists.

Potential impacts on trading

The table shows indicative surveillance actions for mainboard equity. The derivatives and SME provisions differ, so the latest circular should be read for those.

Stage	Short-term ASM	Long-term ASM
Stage 1	Margin of 50% or existing margin, whichever is higher, capped at 100%	Margin of 100%
Stage 2	Margin of 100% or existing margin, whichever is higher, capped at 100%	Price band lowered to the next level, margin 100%
Stage 3	Not applicable	Price band lowered further, margin 100%
Stage 4	Not applicable	Gross settlement, 100% margin and a 5% price band

The long-term stages are not interchangeable with the short-term stages. ASM stage 1 meaning: the first level of restriction, where the margin is raised and the stock comes under closer watch, with 50% or existing margin in short-term ASM and 100% in long-term ASM.

ASM stage 4 meaning: the most restrictive long-term stage. It can involve 100% margin, a 5% price band and gross settlement in the underlying equity, and for stocks with derivatives, additional restrictions on fresh contracts and position limits may apply. The exact conditions for a security depend on the latest exchange circular.

How to Check the ASM List for Stocks?

Step-by-step guide to accessing the ASM list online

The ASM list stock market regulators publish is available free on the exchange websites.

1. Open the NSE ASM page or the NSE circulars section.
2. Find the latest ASM notice or the attached list of securities.
3. Note each security’s symbol, stage and effective date.
4. Open the dated circular for the exact margin, band and settlement conditions.
5. Repeat on the BSE website, which publishes its own list.

The menu names on the exchange sites change from time to time. The ASM stock list NSE publishes is updated with each new notice.

Tools and platforms for tracking ASM stocks

Exchange circulars and dashboards are the primary sources. Many broker platforms also flag ASM stocks on the order screen or stock page, and Jainam’s stocks section is a place to review a company’s price history. Whether Jainam sends ASM-specific alerts should be confirmed with Jainam.

What Are the Implications of Trading Stocks Under ASM?

Impact on stock price volatility

Inclusion does not necessarily cause a price fall or lower volatility. Possible outcomes vary: some stocks cool off as speculative interest fades, while others stay volatile or fall sharply when leveraged positions are unwound. A related read on volatility in the stock market explains why swings can be large even with restrictions in place.

Trading restrictions and margin requirements

A trader who buys Rs 1,00,000 of a stock on the ASM list at 100% margin must fund the entire amount, so leveraged trading is effectively unavailable. 

• At a stage 1 short-term margin of 50%, Rs 50,000 would be needed (an illustration, since the applicable rate is the higher of 50% and the existing margin). 
• Under gross settlement at stage 4, delivery-based rules apply and intraday square-off is not available in the usual way. Brokers may also apply their own risk limits.

How Can Investors Benefit from Understanding ASM?

Informed decision-making

Knowing the stages helps in judging whether a rally rests on fundamentals or on thin, concentrated trading. Checking the list before placing an order avoids surprises on margin, price bands and settlement.

Identifying potential investment opportunities

ASM placement is not a buy or sell signal. A stock that exits the framework after a calm period may be easier to trade, but any opportunity still depends on business quality, valuation and market capitalisation. Care is needed with stocks of very low liquidity.

How a Stock Trading Platform Helps Users Navigate ASM Regulations?

Features of a platform that assists in monitoring ASM stocks

A trading platform can display a stock’s surveillance status on its quote page, show margin requirements before an order is placed, and offer screeners and watchlists for tracking names of interest. The extent of ASM-related features differs by broker, so the current Jainam offering should be confirmed with Jainam.

Providing alerts and updates on ASM changes

Price and news alerts, notifications of circulars and watchlist reminders help catch stage changes early. Exchange circulars remain the final source.

Conclusion

Anyone asking what is ASM in stock market trading can start with this: ASM is a risk-control layer that moves stocks showing unusual trading through graded margins, price bands and settlement rules. Understanding the stages, the review cycle and the margin impact helps traders and investors avoid unexpected restrictions and stay alert to changes.

Final Key Takeaways

• ASM is a surveillance framework, not a verdict on a company’s quality.
• Short-term and long-term ASM have different stages, margins and review periods.
• Long-term stage 4 is the most restrictive and can involve 100% margin, a 5% band and gross settlement, with further limits for derivatives.
• Measures are temporary and reviewed, with at least 90 days in long-term ASM.
• The latest NSE and BSE circulars should be checked before trading any listed stock.

Looking to trade with a broker that offers research and tracking tools? Open a demat account with Jainam.

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