Master methodology v1.3 · §3.7, §3.7A
IOSCO Principle 7 requires benchmark data to be anchored by observable transactions entered into at arm's length in active markets. These screens apply to every candidate within the top 1,500, and the outcomes are published in the audit file. They are applied mechanically and identically to every company; no screen may be waived for a commercial client.
| Screen | The rule | Outcome |
|---|---|---|
| P1 — Trading frequency and depth | A valid session is one with an official close formed from actual trades and at least 5 trades that day. A company needs valid sessions on at least 80% of the sessions it was listed for, and a median daily traded value of at least ₹10 lakh, on each exchange. | An exchange that fails is dropped from the mean, so thin prices never enter the average. If neither passes, the company is ineligible. |
| P2 — Special price-discovery securities | Securities admitted through a special call auction are eligible only if discovery was on or before 1 October and at least 60 valid sessions follow within the window. Only post-discovery sessions are averaged. | Otherwise ineligible for the edition. |
| P3 — Exchange surveillance | Securities under a surveillance framework at any time in the window. | Eligible but flagged, plus mandatory review under P5. Surveillance alone is not proof of wrongdoing. |
| P4 — Regulatory finding | A SEBI interim or final order, up to ranking lock, finding or alleging manipulation of that security's price during the window or the six months before it. | Excluded for the edition, with the decision and reason published. |
| P5 — Unexplained price jump | The window-average price or the 31 December close is more than 5× the average price of the preceding six months, unexplained by a corporate action, listing or disclosed transformational event. | Public flag and review. The Oversight Committee may exclude the security, with written reasons. |
| P6 — Minimum public shareholding | Non-compliance with the minimum public shareholding requirement at 31 December, outside permitted transition periods. | Eligible but flagged. |
The demerger rule
A company whose equity is created by a court- or NCLT-approved demerger from a company that is itself eligible is eligible even if its shares began trading after 1 October, because its value was already part of a ranked listed company throughout the window. Its ranking value is the average over the sessions since its own listing, and it is flagged as a partial-period average. The parent is flagged too. The rule does not apply to IPOs, offers for sale or other first-time listings (§3.7).
Late listings
A company whose ordinary shares commenced trading after 1 October of the measurement year enters the following edition, so that every ranked company has at least about one full quarter of observations. Thirty companies in AMFI's list fall into this category for the Inaugural Edition.
The thresholds — 5 trades, 80%, ₹10 lakh, 60 sessions, 5× — are pilot-gated conventions, not exchange law. Any change to them is a material methodology change and applies only prospectively.