The Hidden Measure That Affects Your Stock Trades

Stock trades depend not only on company results or market trends but also on regulatory checks. Exchanges and the Securities and Exchange Board of India (SEBI) use Additional Surveillance Measures (ASM) to track and control abnormal price movements in listed securities. These measures can affect how investors buy or sell certain stocks.

This article explains the ASM meaning, how the mechanism works, and why it matters for everyday traders.

What is ASM in the stock market?

Additional Surveillance Measures, or ASM, are special monitoring tools that stock exchanges use to control unusual price movements, high volatility, or speculative trading in certain stocks. These measures include stricter rules like higher margin requirements, trade-for-trade settlements, or reduced price bands. The aim is to protect investors and ensure fair trading by preventing market manipulation, especially in stocks with weak fundamentals, low liquidity, or suspicious trading patterns.

Different types of Additional Surveillance Measures list

Based on trading behaviour and risk indicators, stock exchanges classify ASM into different categories. Each type serves a specific regulatory purpose and follows defined criteria. Here are the different kinds of ASM:

1. Long-term ASM (Stage I & II)

This ASM is imposed on stocks showing consistent price movement or abnormal trading over a longer period. Stage I introduces initial restrictions like higher margin requirements, while Stage II includes stricter rules like the trade-for-trade settlement. These are meant to curb manipulation in fundamentally weak or illiquid stocks over the long run.

2. Short-term ASM (Stage I & II)

Short-term ASM targets stocks that show sudden, sharp price movements or excessive volumes in a short period, usually a few days or weeks. It often indicates speculative activity. Stage I apply moderate restrictions, such as higher margins, whereas Stage II can restrict intraday trading completely to prevent quick manipulation.

3. Graded Surveillance Measure (GSM)

GSM is used for companies with poor fundamentals or red flags in financial reporting. These stocks are placed under various stages with increasing trading restrictions, from increased margins to suspension. The purpose is to warn investors and protect them from companies at risk of financial instability or fraud.

4. Trade-for-Trade (T2T) settlement

Under this, every buy or sell must result in the actual delivery of shares; no intraday squaring off is allowed. This reduces volatility and discourages speculative trades. It is often applied to ASM-listed stocks or those with erratic price behaviour.

5. Volatility surveillance

This is triggered when a stock experiences unusual intraday or interday price swings beyond set thresholds. Exchanges may impose special margins and circuit filters or move the stock to a stricter surveillance category. It ensures that trading is based on real market fundamentals, not artificial price rigging.

6. Margin surveillance

Under margin surveillance, exchanges can hike margin requirements significantly for specific stocks to prevent over-leveraging. Traders must bring in more capital to continue trading, which reduces speculative buying. It is applied when stock prices rise or fall rapidly without changing company fundamentals or news flow.

7. Price band adjustments

Exchanges may narrow the daily price movement range (price bands) for stocks under ASM to contain excessive price volatility. For example, a stock earlier allowed to move ±20% may be restricted to ±5%. This limits sharp movements and gives market participants time to assess actual stock value.

8. Illiquidity surveillance

This measure applies to stocks with consistently low trading volumes, prone to price manipulation due to thin order books. Surveillance actions may include moving such stocks to the T2T segment or applying higher margins. It helps prevent artificial price inflation through small trades in illiquid counters.

9. Event-based ASM

Event-based ASM is applied when an upcoming corporate action (like mergers, rights issues, etc.) or regulatory event might impact price stability. The purpose is to prevent speculative trading based on insider news or rumour-driven price activity, ensuring the market remains fair for all participants.

10. Rumour-based surveillance

If a stock’s price suddenly spikes due to unverified news or social media buzz, it may attract rumour-based ASM. Exchanges monitor such activity and can impose restrictions until the company provides clarity. This discourages misinformation-driven speculation and maintains information symmetry in the market.

How do you know if a stock is under ASM?

The National Stock Exchange (NSE) and Bombay Stock Exchange (BSE) publish lists of ASM stocks on their websites. These lists are updated regularly, sometimes daily. You can also:

• Check with your stockbroker (they usually mention ASM in the order screen).
• Use trading apps or websites that show stock status.
• Look for exchange circulars mentioning ASM updates.

Why should you care about Additional Surveillance Measures?

As an investor, ASM can directly affect your trading experience. Here is how:

• Increased margin requirements: When a stock is under ASM, you may be required to deposit more funds to trade it. This means higher upfront costs and potentially lower returns on investment.

• Reduced leverage: Intraday trading options like Margin Intraday Square-off (MIS) or Cover Orders (CO) might be restricted, limiting your ability to take advantage of short-term market movements.

• Trade-to-trade settlement: Some ASM stocks are moved to the trade-to-trade (T2T) segment, where you must take delivery of the shares. This eliminates the possibility of intraday trading and can tie up your capital.

• No pledging allowed: If you have pledged shares under ASM as collateral for loans or margin, you might lose the collateral value, affecting your liquidity.

• Market perception: Stocks under ASM may be viewed as risky or unstable, potentially leading to decreased investor interest and lower liquidity.

Strategies for trading ASM stocks

If you choose to trade stocks under ASM, consider the following strategies:

• Conduct thorough research: Understand why the stock is under ASM and assess whether the underlying issues are temporary or indicative of deeper problems.

• Manage risk: Be prepared for higher margin requirements and potential liquidity issues. Avoid overexposing your portfolio to ASM stocks.

• Monitor regularly: Monitor the stock’s performance and any updates from regulators. ASM status can change, affecting your trading plans.

• Diversify investments: Do not concentrate your investments on ASM stocks. Maintain a diversified portfolio to mitigate risks.

• Consult financial advisors: Seek professional advice to understand the implications of trading ASM stocks and to develop appropriate strategies.

Conclusion

Understanding Additional Surveillance Measures (ASM) is essential if you are trading in the stock market. These rules are not meant to scare you but to protect you from unpredictable and risky stocks. Whether it is high margins, trade-to-trade settlement, or price band restrictions, ASMs aim to keep the market fair and stable. So, before trading, check if a stock is under ASM, research well, and manage your risks smartly to avoid surprises.

Sources

5Paisa
Motilal Oswal