Learn · Surveillance
What are ASM and GSM (the SEBI surveillance frameworks)
ASM and GSM are SEBI and exchange surveillance frameworks that put extra curbs, like higher margins or periodic-only trading, on stocks showing unusual price or volume behaviour.
In one line
ASM (Additional Surveillance Measure) and GSM (Graded Surveillance Measure) are exchange and SEBI frameworks that place a stock under extra curbs, such as up to 100% margin or trading only once a week in higher GSM stages, when its price or volume behaviour looks abnormal.
BazaarBaaziSource & method
ASM: the volatility flag
The Additional Surveillance Measure targets stocks showing sharp price swings, unusual volume, or a high concentration of client activity. It comes in long-term and short-term forms. The most common curb is a jump to 100% margin, which means you must have the full value of the trade upfront, killing the leverage that fuels a momentum chase.
An ASM tag is not an accusation of wrongdoing. It is a brake. The exchange is telling the market that this stock is moving in a way that warrants caution, and it raises the cost of piling in. Many perfectly legitimate stocks pass through ASM during a hot run and exit it when the move cools.
GSM: the graded clamp
The Graded Surveillance Measure is harsher and aimed at stocks with weak fundamentals trading at prices that look disconnected from them, often small caps with thin floats. GSM runs in stages. Early stages add margin requirements, and higher stages can restrict the stock to trade-for-trade settlement or even periodic call auctions, sometimes only once a week, with a price cap on each move.
For a retail investor the practical lesson is simple. A GSM stage tag on a tip you received is a flashing warning that the exchange itself has flagged the name. Liquidity can vanish, you may not be able to exit when you want, and the higher stages exist precisely to trap-proof the kind of pump that lures retail in late.
FAQ3 reader questions · AEO-eligible
Common questions on asm and gsm.
What does it mean when a stock is in ASM?
It means the exchange has placed the stock under Additional Surveillance for unusual price or volume activity, usually adding curbs like higher or 100% margin. It is a caution flag, not proof of manipulation.
Can I buy a GSM stage stock?
Often you can, but with heavy restrictions. Higher GSM stages can limit the stock to periodic trading windows with price caps and full margin, so liquidity and exit flexibility are sharply reduced.
How does a stock get out of ASM or GSM?
The frameworks are reviewed periodically. A stock exits when its price and volume behaviour normalises against the framework's criteria over the review period.
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