SEBI 50:50 Margin Rule Hits F&O Brokers Hard

SEBI's 50:50 Margin Rule Is Already Repricing Brokerage Stocks Picture a retail trader in Pune, mid-2023, running ₹10 lakh in F&O positions backed almost entirely by pledged shares sitting in a demat account. That position would look very different today. SEBI's 50:50 margin rule, now fully in force, requires at least half of all F&O margin requirements to be met in cash or cash equivalents. Pledged securities cover the rest. That one structural change, quiet in its rollout but significant in its impact, is rewriting the economics of derivatives trading across India's ₹400+ trillion annual F&O notional volume. The rule targets a long-standing vulnerability in Indian derivatives markets: traders holding large notional positions financed almost entirely by stock collateral. When markets dropped sharply, those positions unwound in cascades. Pledged shares fell in value, brokers issued margin calls, forced selling accelerated the decline. SEBI saw this loop play out enough times. The fix is blunt but effective: keep real cash in the system. How Brokerage Volumes and Revenue Are Being Squeezed The immediate consequence is capital efficiency loss for active traders. A position that previously needed ₹5 lakh in pledged shares now needs ₹2.5 lakh in cash sitting idle. For high-frequency retail traders running multiple positions, that cash drag compounds fast. Fewer positions means fewer trades, and fewer trades means lower brokerage revenue. It's a straightforward chain. [Angel One](/stock/ANGELONE) (NSE: ANGELONE) feels this most directly. The discount broker built its growth story on retail F&O participation. Its active client base crossed 7 million in FY24, with derivatives contributing a disproportionate share of order flow. Management has already flagged volume softness in recent quarters. With F&O margin requirements tightening further, the revenue-per-active-client metric will compress. Angel One's FairStock Score currently reflects this earnings uncertainty, an...