Risk Reversals And Collars

A protective put is good insurance and a real expense: buying downside protection outright costs a premium, every time, whether or not the crash ever happens. The obvious next question for anyone tired of paying that premium is: can I get someone else to pay for my insurance? A collar's answer is yes — sell away some of your upside, and use the money to buy your downside protection for free, or close to it.

Trading your ceiling for your floor

Think of a landlord offering a tenant a deal: "I'll cap your rent increase at 5% a year no matter what happens to the market, but in exchange, if market rents ever fall, your rent won't drop below what you're paying now either." The tenant traded away the benefit of a falling market for protection against a rising one. A collar does the same thing to a stock position: sell a call at a strike above the current price (giving up gains past that ceiling) and use the proceeds to buy a put at a strike below the current price (guaranteeing a floor). If the premiums happen to match exactly, the whole structure costs zero — a "zero-cost collar." The related trade without owning the stock, buying a call and selling a put at different strikes to lean bullish or bearish for little cash outlay, is called a risk reversal.

The formula

$$\text{Collar payoff}_T = S_T + \big[(K_p - S_T)^+ - P\big] - \big[(S_T - K_c)^+ - C\big]$$

In plain English: you hold the stock ($S_T$), add a bought put struck at $K_p$ that pays off if the stock falls below the floor (net of the premium $P$ you paid), and subtract a sold call struck at $K_c$ that you owe money on if the stock rises past the ceiling (net of the premium $C$ you received). Below $K_p$, the put's payoff exactly offsets further stock losses — your position is flat at $K_p$ no matter how far the stock falls. Above $K_c$, the sold call's obligation exactly offsets further stock gains — your position is flat at $K_c$ no matter how far the stock rises. In between, you simply own the stock. The net cost of the whole structure is $P - C$; choosing $K_p$ and $K_c$ so that $P = C$ gives the zero-cost collar.

Worked example 1: building a zero-cost collar

A stock at $100 that you already own. You want downside protection at $90. The $90 put costs $3.20. You need a call whose premium also equals about $3.20 to make the structure free; checking the chain, the $112 call is quoted at $3.15 — close enough to call this a (near) zero-cost collar. Net cost: $-3.20 + 3.15 = -0.05$, i.e. -$0.05, essentially free. Outcomes at expiry: stock at $70 → protected, your position is worth $90 (the floor) instead of $70, a $20 rescue for a nickel of net premium. Stock at $130 → capped, your position is worth $112 (the ceiling) instead of $130, giving up $18 of upside you would otherwise have kept.

Worked example 2: a bullish risk reversal without owning the stock

A trader with no position wants leveraged upside exposure and is willing to take on downside risk to fund it. Sell the $90 put ($3.20 received) and buy the $112 call ($3.15 paid) — net $0.05 received. This position has no stock at all: below $90 you're obligated to buy stock at $90 (a real loss if the stock keeps falling, since you're short the put), between $90 and $112 you make or lose nothing beyond the nickel collected, and above $112 you participate fully in the stock's rally through the long call. It's a leveraged, low-cost way to express "I think this goes up, and I'm willing to be forced to buy it cheaper if I'm wrong" — functionally similar to a synthetic long position with the strikes spread apart instead of collapsed to one.

Drag the two strikes on this explorer apart and watch the flat floor and flat ceiling appear — move them toward each other and the collar tightens into something closer to a fixed, no-risk payoff; move them apart and it behaves more like plain stock ownership in the middle.

What this means in practice

Collars are the standard way corporate insiders and concentrated single-stock holders (executives with large vested equity positions) protect wealth without triggering a taxable sale — the stock is never sold, only options are added around it. Risk reversals, quoted routinely in FX markets as "25-delta risk reversal," are also the standard way traders express and measure skew: if out-of-the-money puts are consistently more expensive than equally-far calls, the risk reversal has a persistent negative cost, which is a direct, tradable readout of the market's skew — see Risk Reversals and Butterflies.