GSM and ASM: How NSE/BSE Surveillance Affects Your Stock Trades

The National Stock Exchange (NSE) and Bombay Stock Exchange (BSE) implement various surveillance mechanisms to ensure market integrity and protect investors. Two such important measures are the Graded Surveillance Measure (GSM) and the Additional Surveillance Measure (ASM). **What is GSM (Graded Surveillance Measure)?** GSM is a regulatory framework initiated by SEBI and implemented by exchanges to monitor stocks that show an abnormal price increase inconsistent with their financial health and fundamentals. The idea is to caution investors and advise them to be extra careful while dealing with such securities. GSM is typically applied to stocks that are perceived to be vulnerable to rampant speculation or price manipulation. **How does GSM work?** Stocks under GSM are categorised into six stages (Stage 1 to Stage 6), with each successive stage imposing stricter surveillance and trading restrictions. These restrictions can include a 100% margin requirement, reduced trading frequency (e.g., weekly or monthly once), and a cap on the maximum price movement permitted. Moving to higher stages indicates more severe concerns about the stock's behaviour. **What is ASM (Additional Surveillance Measure)?** ASM, like GSM, is another surveillance mechanism to keep a check on volatile stocks. It aims to identify and monitor securities that exhibit unusual price and volume movements, often seen as potential indicators of manipulation or excessive speculation. ASM provides an early warning system for investors and exchanges alike. **How does ASM work?** Stocks under ASM are also categorised into stages (Stage I and Stage II, at present). The restrictions for ASM typically involve placing the stock under a 100% margin requirement and implementing a price band reduction. These measures are designed to curb excessive speculation and bring more stability to the stock's trading. **Impact on Retail Investors:** If a stock you own or are considering buying enters the GSM or ASM list, it can significantly impact your trading experience. The increased margin requirements mean you'll need more capital to trade these shares. The reduced trading frequency (for GSM) can make it difficult to enter or exit positions quickly. While these measures can reduce liquidity and increase holding costs, their primary goal is to protect you from potentially manipulated or excessively volatile stocks. Always research thoroughly before investing in such scrips.