Eligibility criteria for selection of stocks for derivatives trading

SEBI (Securities and Exchange Board of India) and the two recognised stock exchanges – NSE and BSE – prescribe the rules for admitting a stock to the derivatives segment. The guidelines are issued as circulars and are periodically updated to reflect market conditions. For the NISM exam, remember that the authority is SEBI, while the implementation details (such as exact turnover thresholds) are set by the exchanges.

The eligibility framework serves two purposes: it protects market participants from ill‑liquid securities and it ensures that the underlying asset can support the price discovery mechanism of futures and options. A stock that fails any of the mandatory tests cannot have a derivative contract listed, even if it is heavily traded in the cash market.

Exam questions often ask you to pick the correct statement about eligibility or to identify a stock that would be excluded. Focus on the five core parameters – market capitalisation, average daily turnover, free‑float, price band compliance and corporate actions – as they appear repeatedly in the syllabus.

The first quantitative filter is minimum market capitalisation. Exchanges typically require a stock to have a market cap of at least a few hundred crore rupees. This ensures that the underlying company is of sufficient size to sustain price movements without being overly volatile.

Second, the average daily turnover (ADT) over the preceding 30 trading days must cross a defined threshold. ADT reflects the liquidity of the security – higher turnover means tighter bid‑ask spreads and smoother futures/options pricing.

Third, the free‑float percentage – the proportion of shares that are publicly tradable – must be above a minimum level (commonly 25%). A low free‑float can lead to price manipulation and thin trading, which are undesirable for derivative contracts.

In addition to these numbers, the stock must comply with the price band rule (no extreme price volatility) and must not be under any corporate action that could affect share price continuity, such as a pending split or merger.

The ADT formula is straightforward but appears in many exam scenarios. Remember to use the same period (usually the last 30 trading days) that the exchange specifies. The result is expressed in rupees per day and is compared against the minimum turnover threshold.

If a stock’s ADT falls short, it is automatically barred from the derivatives segment, regardless of its market cap or free‑float. Conversely, a stock that meets the ADT but fails the free‑float test will also be excluded.

Exam tip: When a question provides total turnover and number of days, compute ADT first and then match it against the given threshold. Do not confuse ADT with average daily volume (shares); the formula uses monetary turnover.

Free float is calculated as the percentage of total issued shares that are held by the public and are not locked in by promoters, insiders, or the government. The formula is:

Free‑Float % = (Publicly Traded Shares ÷ Total Issued Shares) × 100

While the syllabus does not require you to compute this value, you must know the definition because many exam questions test your understanding of why a high free‑float is essential. A free‑float below the prescribed limit can lead to price volatility and manipulation, making the stock unsuitable for derivatives.

Exchanges enforce a price band rule for derivative‑eligible stocks. The stock’s closing price must stay within a pre‑defined percentage (typically 10%) of its previous day’s close. This prevents extreme price swings that could destabilise futures and options pricing.

Additionally, the underlying must not be under any corporate action that could cause a sudden price jump, such as a dividend announcement, rights issue, or stock split, within the next 30 days. Such actions are flagged in the exchange’s corporate actions calendar.

For the exam, remember that price band compliance is a qualitative check, whereas market cap, ADT, and free‑float are quantitative. Questions may ask you to identify which of the following stocks fails the price‑band test.

The selection workflow begins with the exchange’s surveillance team pulling the latest market data for each listed equity. The data is fed into a compliance engine that automatically checks the quantitative thresholds – market cap, ADT, and free‑float.

If a stock clears the quantitative gate, the compliance team reviews qualitative aspects: price‑band adherence, pending corporate actions, and any regulatory restrictions. The final decision is recorded in the exchange’s derivatives eligibility register.

For the exam, visualise this as a two‑stage filter – quantitative first, then qualitative. Many multiple‑choice questions present a list of stocks and ask which one will be rejected; applying the filter order quickly eliminates candidates.