When the Reserve Bank of India's new bank guarantee rules finally took effect on July 1 — after brokers and prop desks failed, for the second quarter running, to win a reprieve — the consensus view was that MCX would be the exchange left standing. Commodity derivatives were futures-heavy, the argument went; the options-inventory warehousing problem that analysts flagged as the rule's biggest casualty didn't map onto crude and gold futures; and years of regulatory and tax attrition had supposedly already wrung the leverage out of the segment. This publication made a version of that argument last week.
The first three trading sessions of July have dismantled it. MCX premium turnover fell on Wednesday, fell further on Thursday, and dropped again on Friday — a sequential grind lower that market participants attribute squarely to the RBI's new collateral norms, whose bite is proving significantly larger than anticipated. Equirus, reviewing the first sessions after the circular took effect, noted that the pullback in options premium turnover was not confined to BSE — where expiry-day volumes ran as much as 24-37% below early-June levels — but extended to MCX, which reported "a similar pullback in recent sessions." The irony is sharp: MCX's options franchise entered July with momentum, with options average daily turnover rising 8% month-on-month in June even as futures turnover fell.
The number everyone missed: 60%
The reason MCX is being hit harder than the futures-heavy-book thesis predicted sits in the clearing data, not the product mix. What the RBI rule attacks is not options versus futures — it is how members fund their margins. And on that measure, MCX is the most exposed venue in India, not the least.
Data from the clearing corporations — ICCL, NCL and MCXCCL — shows total margins held across equities and commodities stood at ₹9,750 billion (about ₹9.75 lakh crore) as of December 2025, up nearly 19% from ₹8,209 billion a year earlier. MCXCCL's share of that pool is small: ₹546.5 billion, or barely 6% of industry margins, against roughly 9% for BSE's ICCL and about 86% for NSE's NCL.
But composition, not size, is what matters now. Of MCXCCL's ₹546.5 billion margin book, ₹324.2 billion — 59.3% — sits in fixed deposits and bank guarantees, the two bank-intermediated instruments at the centre of the RBI's clampdown. At BSE, the comparable figure is about 30% (₹256.6 billion of ₹850.4 billion). At NSE's clearing corporation, the implied figure is around 34% (₹2,838 billion of ₹8,353 billion). MCX's clearing house is nearly twice as dependent on bank paper as either equity-market peer.
The rest of MCX's margin book offers little cushion. Cash margin held from brokers is just ₹56.9 billion, or about 10% of the total. Government securities — the collateral class untouched by the new rules — account for under 10%. Equities pledged as collateral (₹72.9 billion, roughly 13%) now attract the RBI's minimum 40% haircut, and mutual fund units (₹27.8 billion) face similar treatment. Add it up and barely a quarter of MCXCCL's margin pool — cash, G-secs and its small, distinctive ₹10.9 billion book of non-cash gold — sits in instruments the new framework leaves alone. Roughly three-quarters is either directly constrained or newly haircut.
Why commodity desks leaned hardest on the banks
The concentration is not accidental. Commodity derivatives carry some of the highest margin rates in Indian markets — crude oil and natural gas contracts routinely demand initial margins in the mid-teens, spiking higher in volatile phases. For the mid-sized, often non-metro prop desks and brokers who dominate commodity flow, posting that margin in cash was never economical. A bank guarantee obtained against 50% margin — often itself an FD — let a member place ₹100 of collateral at MCXCCL while tying up a fraction of that in own funds. Under the new Commercial Banks – Credit Facilities Amendment Directions, 2026, every such guarantee must now be backed by 100% collateral, at least half in cash. The cheap leverage is gone, and it is gone from precisely the venue whose members used it most intensively.
This is the same mechanism that Bloomberg described as a "body blow" to the domestic prop industry — Karna Stock Broking's Karthik P estimated effective trading capacity for BG-reliant firms would halve, from about 1.7 times capital to 0.85 times — but its geography was misread. The estimates circulating before July 1 focused on equity index options, where prop desks account for roughly 40% of flow, and treated MCX as a sideshow. The clearing data inverts that: in proportion to the size of its margin pool, no exchange has more member funding at stake than MCX.
A double asymmetry
MCX also lacks the shock absorbers its equity peers can call on. NSE's options complex has a deep, layered base — foreign HFTs through the FPI and GIFT City routes, institutional desks, an enormous organic retail book — that can backfill a domestic prop desk's exit. Even BSE, for all its wholesale-driven fragility, sits on the same Sensex-linked retail pipes. MCX's flow is far more dependent on exactly the domestic proprietary and jobbing community now facing the collateral squeeze, and foreign market makers cannot simply replace them: banks, insurers and most foreign portfolio flows remain restricted in commodity derivatives — a stance SEBI's own chairman confirmed RBI and IRDAI continue to hold. The rule squeezes MCX's core liquidity providers while regulation keeps the substitutes locked out. That is the reverse of the equity market's cushion, and it is why the exchange that looked structurally safest is now printing three straight sessions of shrinking premiums.
None of this shows up yet in official statistics — MCX will disclose July turnover in its monthly data, and the first clean read on margin unwind will come when clearing corporations report post-implementation collateral composition. But the direction is visible on the tape, and the mechanism is visible in the December margin book. The market spent June debating which exchange's options volumes the RBI had just repriced. It may have been asking the wrong question. The rule was never really about options. It was about who had been renting their balance sheet from a bank — and by that measure, MCX was always first in line.
________________________________
Margin data as of December 2025; source: ICCL, NCL, MCXCCL. BSE cash margin assumed at 2% of total as ICCL clubs cash, FDs and BGs. NSE figures derived as industry totals minus BSE and MCX. |
