Stock and commodity exchanges and their clearing corporations, which match, clear and guarantee every trade.
Runs the order-matching engines for shares, derivatives and commodities, guarantees settlement through its clearing corporation, and sells listings, indices (Nifty, Sensex), market data and co-location. Revenue is a small charge on the value (or option premium) of each trade.
This is the chain's biggest and most profitable pool: NSE alone handles ~93% of cash trading and nearly all equity futures, with very high operating margins. But it is also where regulation bites first - options are the largest revenue line, and SEBI's curbs and BSE's revived Sensex options moved share and earnings within a year.
Exchange revenue is mostly transaction charges (about four-fifths of NSE's revenue in FY26, per its RHP), with equity options the single largest line. Costs are largely fixed technology and regulatory contributions, so volume swings drop straight to profit. MCX is a near-monopoly in commodity derivatives, now driven by bullion options.