Market Makers

Chapter 4 revealed the spread as a toll. Meet the toll collector.

A market maker is a firm that continuously quotes both sides — a bid and an ask — in an instrument, all day. Post ₹99.95 bid / ₹100.05 ask, get hit on both sides, earn 10 paise, repeat thousands of times daily. Individually tiny, collectively a business. The market maker is the "patient side" from Chapter 4, industrialized.

But the rent isn't free money — it pays for a genuine risk called inventory risk (also adverse selection): after buying from a seller, the maker holds the instrument until someone buys it back — and if price moves against them in that gap, one bad move can erase hundreds of collected spreads. Worse: sometimes the person hitting their quote knows something (news is breaking), and the maker is systematically on the wrong side of informed traders. Their entire craft is pricing these risks into the spread — which finally explains, mechanically, why spreads widen exactly when you most want to trade: in fast or uncertain markets, inventory risk explodes, so makers widen quotes or step away, and the toll rises precisely at the moment of panic. Not malice — self-preservation, priced.

Why this matters enormously for options traders (i.e., you): in most option strikes, especially away from the money, the counterparty to your trade is almost always a market maker — retail-to-retail matches are rare out there. Makers quote options using pricing models and hedge their inventory instantly in the underlying (the mechanics of that hedging is called delta hedging — your Options school territory). Two practical consequences: option spreads are the maker's risk assessment of that strike (wide spread = "this strike is hard/risky to hedge"), and quoting limit orders inside the spread often gets you filled at better-than-screen prices, because you're offering the maker a cheaper trade than crossing to the far side — free money left on the table by every trader who market-orders options by default.

One myth to retire: "market makers hunt my stop-loss." Makers profit from flow and spread, not from your individual 50-lot position — they neither know nor care about your stop. The stop-hunting phenomenon is real but has a structural, crowd-based explanation — Chapter 14 gives it to you properly, without the conspiracy.