NextFin News - India's National Stock Exchange is the world's largest equity derivatives venue, a market that turned over trillions in notional volume on a simple bargain: proprietary trading firms brought the leverage, the algorithms, and the liquidity, while millions of retail investors brought the losses. That bargain is ending. A coordinated regulatory squeeze — a market-manipulation crackdown that impounded ₹4,843 crore from Jane Street, a Reserve Bank of India rule banning bank funding for proprietary trading, and a suite of exchange-level curbs on weekly expiries and contract sizes — has pushed the prop desks that once accounted for nearly half of NSE derivatives turnover into retreat. The question now is not whether volumes fall, but whether the market that emerges is structurally smaller, and what that means for an exchange preparing for India's biggest-ever initial public offering.
The Situation: A Market Cooling at Speed
The numbers show a market cooling at speed. In fiscal 2026, total options contract volumes on India's stock exchanges fell 51.5% from the prior year, and index options turnover across the National Stock Exchange and the Bombay Stock Exchange dropped 52%, according to the securities regulator's annual report. The slowdown accelerated into the final quarter: index options turnover fell about 15% year-on-year in the three months to March, while stock futures, index futures, and stock options each contracted roughly 30%. By late August, premium turnover on the NSE had sunk to about ₹67,000 crore on a monthly expiry day — the lowest level since December — and cash-equity volumes hit their weakest point since November.
The pullback is concentrated where the prop desks live. Proprietary traders — firms that trade with their own capital rather than client money — generated the highest gross trading profit of any participant category, about ₹44,000 crore in fiscal 2026, followed by foreign portfolio investors at about ₹14,000 crore. The regulator's study found that 99% of the profits earned by prop firms and foreign investors came from algorithmic trading entities. In other words, the most profitable players are also the most mechanized, and they are the ones now facing the highest regulatory cost.
The squeeze has three distinct pressure points. First, enforcement: on July 3, 2025, the Securities and Exchange Board of India accused four Jane Street entities of manipulating the Bank Nifty index across 18 expiry days between January 2023 and March 2025, directing the firm to deposit ₹4,843.57 crore in alleged unlawful gains into escrow. Second, funding: from April 1, 2026, the RBI prohibited banks from lending for proprietary trading and required 100% collateral for other broker financing, with the rules taking full effect in July. Third, market structure: from November 2024, SEBI raised contract sizes, trimmed the number of weekly expiries, mandated upfront premium collection, and lifted the securities transaction tax.
The immediate consequence is a volume shock with direct revenue implications. Options generated about ₹10,000 crore in transaction charges in the year ended March, accounting for 60% of the NSE's revenue from operations, according to the exchange's IPO filing. A shrinking options book is therefore not a peripheral concern for an exchange heading into a landmark public listing.
Why the Prop Model Broke: It Was Leverage, Not Genius
The first-order explanation is simple: prop desks borrowed cheaply and traded expensively. Under the pre-April regime, trading firms used bank financing to ramp up leverage, earning spreads on positions that were collateralized only partially. The RBI's new rules remove both advantages at once. Banks can no longer fund proprietary books at all, and any other credit must be fully collateralized. Executives at six trading firms said the changes could cut profit margins in half and reduce derivative volumes by as much as a fifth.
That is a mechanism, not merely a cost increase. A prop desk's edge in India's options market was never purely informational; it was a funding-arbitrage edge compounded by speed. When cheap leverage disappears, the expected return on the same strategy falls below the hurdle rate, and capital rotates elsewhere.
Domestic proprietary trading firms fear that their business model has been rendered obsolete.
One executive at a mid-sized Indian prop firm said as much. The head of a large domestic high-frequency trading firm was more measured: large firms still have their own capital to deploy, but growth prospects are impaired.
The distinction matters. This is not a uniform exit. The firms most exposed are the smaller prop shops that historically relied on broker funding and lack large balance sheets or alternative credit access, according to a note from IIFL. Larger, better-capitalized desks — including some foreign players with global funding lines — can absorb the shock. The market is not losing prop trading; it is losing the marginal, highly leveraged prop trading that dominated expiry-day flows.
The Structural Call: This Is a Regime Change, Not a Cycle
Is the pullback cyclical — a temporary retreat that reverses when sentiment improves — or structural? The evidence points to structural. Three tests separate the two.
A cyclical decline needs a short-term, self-correcting driver: a liquidity squeeze that eases, an inventory build that clears, a sentiment shock that fades. The drivers here are the opposite of self-correcting. The RBI's funding prohibition is a permanent rule, not a temporary facility. SEBI's contract-size increases and expiry rationalization are not scheduled to reverse. The Jane Street enforcement action established a precedent — the regulator's willingness to impound billions and restrain market access pending proceedings — that raises the cost of aggressive expiry-day strategies permanently.
A structural shift needs evidence that the old equilibrium cannot return. India's derivatives market grew to more than double the size of the underlying cash market — a derivatives-to-cash ratio above 200%, versus 2% to 3% in major global markets. That gap was the regulatory anxiety that motivated the crackdown. Policymakers are not trying to restore the old volume peak; they are trying to prevent it from ever recurring. The SEBI study shows the measures are working exactly as designed: the share of index-options turnover occurring on expiry day fell to 59% in FY26 from 70% in FY25, and turnover within one day of expiry fell to 75% from 80%. Activity is being deliberately redistributed away from the zero-days-to-expiry trades where prop desks concentrated.
The historical comparison reinforces the call. Previous regulatory attempts — higher fees, fewer contracts, higher taxes — reduced the number of contracts traded but left total trade value high, suggesting capital kept deploying. The RBI funding curbs attack the capital itself. When the constraint moves from "how much can you trade" to "how much can you borrow," the adjustment is deeper and more durable.
The Second-Order Effect: Retail May Not Fill the Gap
The conventional read of the prop pullback is that it creates room for retail investors — fewer sophisticated players, a fairer market. That is the first-order comfort, and it is probably wrong.
The second-order transmission runs through liquidity. Prop desks supplied the tight bid-ask spreads and the depth that made high-frequency retail options trading viable. When Nithin Kamath, founder and chief executive of Zerodha, warned in July 2025 that prop firms like Jane Street accounted for nearly 50% of options trading volumes, he did not frame their exit as a retail opportunity.
If they pull back — which seems likely — retail activity (about 35%) could take a hit too. So this could be bad news for both exchanges and brokers.
The logic is counterintuitive but sound: retail traders are not independent actors; they are liquidity followers. When spreads widen and expiry-day volatility becomes less predictable — partly because the closing-auction mechanism introduced in August reshaped the final 20 minutes of trading — the same retail cohort that chased momentum finds fewer clean exits. The SEBI data already hints at this: the number of individual derivatives traders fell about 20% in fiscal 2026, and while their aggregate net losses declined to about ₹91,685 crore from ₹1.12 trillion, the improvement came more from participants leaving than from participants winning.
There is also a compositional twist. The regulator's combined FY25–FY26 study recorded aggregate individual losses of ₹203,473 crore across 12.26 million traders, an average loss of ₹166,000 per person. A market that becomes structurally less liquid does not automatically become kinder to those traders; it becomes a market where the cost of being wrong rises.
The Counter-Thesis, and What Would Prove It Wrong
The strongest argument against the structural call comes from the exchange's own stakeholders.
The decline in options volumes is a challenge for NSE ahead of its IPO. But we see this as a short-term hiccup rather than a long-term concern.
Kranthi Bathini, an equity strategist at WealthMills Securities, made the case. It rests on three pillars. First, India's derivatives penetration remains low relative to the size of the economy and the equity market, implying a long runway for growth. Second, the NSE retains a dominant market position, accounting for 70% of global index options trades by the World Federation of Exchanges' measure, and competitive pressure from the BSE is limited. Third, market participants adapt: once the closing-auction mechanism is understood and funding alternatives emerge, volumes can stabilize at a lower but still-large level.
The counter-thesis is coherent, but it conflates "the NSE remains dominant" with "the prop-driven volume peak returns." Those are different claims. Dominance is about market share; the structural call is about the absolute size of the pie. The exchange can keep its 70% global share while trading far fewer contracts than in fiscal 2025. The more damaging weakness in the counter-thesis is its treatment of leverage. If volumes recover to prior peaks without a restoration of cheap bank funding, the recovery must be funded by equity capital — which demands a higher return and tolerates less risk. That math does not produce the old volume curve.
The falsifying signal is specific and observable: if monthly index-options premium turnover on the NSE returns to and sustains levels above ₹100,000 crore for three consecutive months while the RBI funding prohibition remains in force, the structural-decline thesis is wrong. That would demonstrate that prop desks have found alternative funding at scale, or that retail and institutional flows can replace leveraged prop capital without a liquidity premium. Until that prints, the burden of proof sits with the recovery case.
Conclusion: The Leverage Regime Is Gone
The impact of the prop pullback stratifies cleanly by time horizon.
In the short term, the losers are the most visible: smaller prop firms without balance-sheet depth, brokers whose revenue is tied to turnover, and the NSE as it markets its IPO. Transaction charges from options — 60% of the exchange's operating revenue — are the direct exposure.
In the medium term, the question is whether liquidity finds a new equilibrium. Base case: volumes stabilize at 40% to 60% below the fiscal 2025 peak, spreads remain somewhat wider, and the market becomes less attractive to high-frequency retail churn. Upside case: the closing-auction mechanism beds down, foreign capital returns under the clarified enforcement regime, and volumes recover toward the ₹100,000 crore monthly threshold. Downside case: funding alternatives fail to emerge, more prop desks shift operations offshore, and the market enters a multi-year consolidation.
In the long term, the structural call implies a different kind of market. India's derivatives-to-cash ratio, above 200% against 2% to 3% globally, was always a policy target, not a sustainable equilibrium. A market that converges toward global norms is smaller by design. That is the intended outcome of the crackdown — a less leveraged, less expiry-obsessed market — and it is the outcome now arriving.
The final judgment: the prop retreat is not a temporary withdrawal awaiting the next bull run. It is the unwinding of a leverage-fueled regime that regulators deliberately dismantled, piece by piece, from the Jane Street enforcement action through the RBI's funding ban. Volumes may bounce on sentiment; the structure that produced the $2 trillion peak is gone.
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