SEBI Tightens Stock Derivative Rules, Ups Margins 30-60%

Securities and Exchange Board of India (SEBI) is poised to significantly alter margin requirements for single-stock derivatives. The regulator plans to withdraw the calendar spread benefit on contract expiry days, a move expected to increase margin outlays by 30% to 60% for many leveraged traders. This regulatory shift brings single-stock derivative treatment in line with index derivatives, where similar offsets were removed earlier this month.

Rationale Behind the Rule Change

The core objective is to mitigate systemic risks. Currently, traders utilize calendar spreads – holding futures or options across different expiries – to benefit from lower margins recognized by clearing corporations for offsetting risks. However, when one leg of the spread expires after market hours, the remaining open position suddenly attracts full margin requirements. This creates a "risk window" for trading members, potentially leading to margin shortfalls if clients fail to top up funds, especially after sharp overnight price movements. By demanding higher margins intraday on expiry days, SEBI aims to give brokers more time to manage exposures before the market closes.

Market Implications and Trader Adjustments

Calendar spread benefits will continue for positions involving non-expiring contracts, such as spreads between next-month and far-month expiries, even on the current month's expiry day. The new framework is slated to take effect three months after the circular's issuance. While intended to enhance market stability by reducing overnight risk, market participants anticipate potential side effects. Higher intraday margin demands might compel leveraged traders to unwind spread positions earlier in the session. This could lead to thinner order books, wider bid-ask spreads, and more volatile price action near expiry. Smaller, capital-constrained traders who rely on margin offsets may reduce their participation, particularly in high-volume single-stock futures.