Short-term ASM (ST-ASM): stages I and II, margins and review

Last reviewed 13 October 2026 · by Rachid Asen

Short-term ASM is the two-stage part of the Additional Surveillance Measure, for sharp price moves over days or weeks with concentrated trading. Its measures are higher margins, and a stock is reviewed after 5 or 15 trading days.

Stage I: what puts a stock there

According to NSE's FAQ on ASM (last updated 20 September 2024), a stock is shortlisted when it meets any of these:

• a close-to-close price variation of at least 25% (up or down) plus its beta times the Nifty 50's move over 5 trading days, with the top 25 clients at 30% or more of the combined NSE and BSE volume in those 5 days;
• the same with at least 40% over 15 trading days, and the top 25 clients at 30% or more of the volume in those 15 days;
• for a market capitalisation above ₹100 crore and up to ₹500 crore, a one-month high-low variation above 75% with fewer than 100 unique PANs trading the stock on average in the last month; above ₹500 crore, the same with fewer than 200.

Measures in Stage I: the exchange asks the company to clarify any announcement not yet made public and shares the reply with the market, shows the stock on a surveillance dashboard, and sets the margin at 50% or the existing margin, whichever is higher, up to 100%.

Stage II

A Stage I stock moves to Stage II if its close-to-close price variation reaches at least 25% (up or down) plus its beta times the Nifty 50's move in any 5 consecutive trading days within the 15 days after it entered Stage I, or in any 15 consecutive trading days within the 45 days after it entered, with the top 25 clients at 30% or more of the combined volume in that period.

Measures in Stage II: 100% margin, or the existing margin if higher, up to 100%.

Measures as published in NSE's FAQ on ASM (last updated 20 September 2024), checked on 13 October 2026. The exchanges change them by circular; the current circular applies.

Review and exit

• A stock stays in each stage for at least 5 or 15 trading days, and is reviewed from the 6th or 16th trading day.
• A stock that does not meet the entry criteria on the review date moves out of short-term ASM.
• While it keeps meeting the criteria without attracting long-term ASM, it stays in Stage II. If it moves to long-term ASM, the short-term provisions stop applying.

SME and derivative stocks

Short-term ASM also covers SME stocks, with thresholds measured against a broader index (circular NSE/SURV/58558, 25 September 2023), and stocks with derivatives, where the 50% and 100% margins also apply to their futures and options (circular NSE/SURV/52144). The exact rules are in the FAQ linked under Sources.

Sources

• NSE: FAQs – Additional Surveillance Measure (ASM), last updated 20 September 2024: shortlisting criteria, long-term stages I–IV, short-term stages I–II, review and exit. It cites circulars NSE/SURV/52090 (22 April 2022, long-term ASM) and NSE/SURV/52144 (28 April 2022, short-term ASM).
• NSE: Additional Surveillance Measure (ASM): the framework's parameters and NSE's list of shortlisted securities.
• BSE: Additional Surveillance Measure (ASM) and BSE: FAQs on ASM: BSE's circulars, its long-term and short-term ASM lists, and its daily “Applicability of Additional Surveillance Measure” notices.

Exchange circulars change. Where this page and the current circular differ, the circular applies.

Not investment advice. This page explains the exchanges' published rules for education only. It does not recommend buying, selling or holding any security. Inclusion, stage changes and exit are decided solely by NSE and BSE.