Understanding ASM and GSM Surveillance
If a stock lands in ASM or GSM, trading it gets restricted. Here’s what these surveillance measures mean.
On this page
ASM and GSM are surveillance frameworks that exchanges and SEBI use to protect investors from excessive speculation and potential manipulation in certain stocks. If a stock enters these lists, trading it becomes more restricted.
ASM — Additional Surveillance Measure
A stock can be placed under ASM due to unusual volatility, sharp price swings, or abnormal volume. Being under ASM typically triggers:
- Higher margins — you must put up more money to trade it.
- Tighter circuit limits — smaller allowed daily price moves.
- Sometimes a shift to trade-for-trade (T2T) settlement, where intraday netting isn’t allowed and every trade must be settled by delivery.
GSM — Graded Surveillance Measure
GSM targets stocks with weak fundamentals trading at unusual valuations — often illiquid penny stocks. GSM has graded stages with escalating restrictions, from higher margins up to trading allowed only periodically with heavy deposits.
What it means for you
- A warning sign — a stock under ASM/GSM is flagged for a reason; treat it with extra caution.
- Higher cost and risk — bigger margins and restricted settlement make trading harder and costlier.
- Liquidity risk — you may struggle to exit, especially in GSM stocks.
If you hold or are tempted by a stock under surveillance, understand why it’s there before acting. These measures exist to protect you. Education only, not a recommendation.
