NSE Surveillance Measures - GSM, ASM, ESM Explained

The VIGIL Surveillance view shows companies that NSE and SEBI have placed under special monitoring. When a stock's price movements seem unusual compared to its financial health, or when there are other risk indicators (insolvency, high pledging, compliance failures), the exchanges flag these companies with specific measures. The data comes from NSE's daily surveillance indicator file (REG_IND), which lists every listed security and its current surveillance status; VIGIL shows only the flagged companies - those with at least one active surveillance measure or risk flag.

Open the live VIGIL Surveillance view for the current list of flagged companies and their stages.

GSM - Graded Surveillance Measure

GSM targets stocks whose prices are not justified by their financial fundamentals - earnings, book value, net worth, and PE ratio. SEBI and NSE jointly identify such companies every quarter and place them into progressively restrictive stages.

Current framework: 4 stages

ASD (Additional Surveillance Deposit): paid by the buyer only, collected in cash on T+1, and not refundable even if the shares are sold later. This is over and above normal trading margins.

Stage IV is the most severe - trading only once a week, the buyer puts up a 100% cash deposit, and the stock price cannot go up. This effectively makes it nearly impossible to buy.

Introduced Feb 2017; reduced from 6 to 4 stages in Nov 2019. Reference: NSE GSM FAQ (Apr 2025).

ASM - Additional Surveillance Measure

ASM targets stocks with unusual price/volume patterns. Unlike GSM (which looks at fundamentals), ASM focuses on trading activity - sudden price spikes, unusual volume, concentrated buying by a few clients, or low delivery percentage. There are two sub-types.

Long Term ASM (LT-ASM): 4 stages

Intraday trading is blocked across all LT-ASM stages. Minimum 90 days in the framework before exit.

Short Term ASM (ST-ASM) is a lighter, temporary measure. Since September 2024 it is a single-stage 100% margin requirement - no Trade for Trade, no price-band change. It usually lasts a week to a month with weekly review.

References: NSE ASM FAQ · Circular SURV/67801 (Sep 2024).

ESM - Enhanced Surveillance Measure

ESM specifically targets micro and small-cap companies (market cap under Rs 500 crore) showing extreme price volatility. Unlike GSM (fundamentals) or ASM (trading patterns), ESM looks at the high-low price variation over 3, 6, and 12 months.

2 stages:

Minimum 90 days in the ESM framework before exit; weekly review for stage movement. Introduced June 2023. Reference: NSE ESM FAQ (Oct 2024).

Other surveillance flags

IRP - Insolvency Resolution Process

The company has been admitted to the Corporate Insolvency Resolution Process (CIRP) by NCLT under the Insolvency and Bankruptcy Code (IBC), 2016. The company's assets are frozen for review and creditors work to resolve the debt; outcomes can include restructuring, new ownership, or liquidation. This is the most serious corporate-distress flag.

ICA - Inter-Creditor Agreement

The company's lenders (banks / NBFCs) have signed an Inter-Creditor Agreement under RBI's framework to collectively resolve the company's debt stress, outside the formal NCLT/IBC process - a pre-insolvency stage where lenders try to fix the trouble without going to court.

Loss Making

The company has reported net losses in recent quarters. No trading restriction is imposed, but a mandatory alert is shown to investors, and it is used alongside other criteria for GSM/ESM identification.

Encumbered over 50%

More than 50% of the company's total shares are encumbered (pledged, under lien, or non-disposal undertaking). High encumbrance means a large portion of shares are locked as collateral; if the stock price falls sharply, lenders can force-sell these shares, creating a downward spiral. See the Promoter Pledge and Encumbrance pages for detail.

Pledge Flagged

Promoter pledge data meets specific surveillance criteria. Promoter pledging above 20% of their own shareholding is a GSM exit blocker - the company cannot leave GSM's periodic call-auction stage until pledge comes below 20%.

BZ / SZ Series

The stock has been moved to BZ (mainboard) or SZ (SME) series due to LODR compliance violations. Trading is restricted to a Trade-for-Trade basis with no intraday. This is a regulatory penalty, not a surveillance measure.

Listing Fee Default

The company has not paid its annual listing fee to NSE. Actions escalate from public disclosure, to a warning on the company's quote page, to the stock being moved from EQ to BE series (Trade for Trade), to potential suspension and delisting.

NSE series codes

Each stock on NSE trades under a specific series code. The series determines settlement type, whether intraday is allowed, and the trading platform.

Reference: NSE Legend of Series (official).

Company name coverage

Company names on the Surveillance view come from NSE's master list of mainboard equities (EQUITY_L.csv), which covers ~2,200 mainboard stocks (EQ, BE, BZ series) but does not include SME platform stocks (SM, ST, SZ series) - NSE EMERGE is a separate segment with its own listing rules and a separately maintained master list. About 100 of the ~400 flagged companies are SME stocks, which is why some names are blank. VIGIL supplements with names from its other tables (insider trading, SAST, encumbrance, credit ratings), bringing overall name coverage to approximately 87%.

References and circulars

GSM: NSE GSM FAQ (April 2025); NSE/SURV/34262 (Feb 2017, original framework); NSE/SURV/42790 (Nov 2019, 6 to 4 stages).

ASM: NSE ASM FAQ; NSE/SURV/67801 (Sep 2024); NSE/SURV/61848 (LT-ASM stages).

ESM: NSE ESM FAQ (Oct 2024); NSE/SURV/56948 (Jun 2023, introduction); NSE/SURV/57609 (Jul 2023, stage II daily call auction).

General: REG_IND Annexure (file format); NSE Legend of Series.