What is a Put Option? A Beginner's Guide

Put options are the most misunderstood instrument in the retail toolkit. They are the closest thing the market has to insurance, and they were used as exactly that by a small group of hedge funds, Cornwall Capital, Scion Capital, Paulson and Co., to convert a few hundred million dollars into tens of billions when the US housing market collapsed in 2007 and 2008. That trade is now part of financial folklore.

The same instrument, deployed at retail size against weekly moves in a Top 40 share, is more likely to function as a steady donation to the option writer. The mechanics are identical. The outcomes diverge because the use cases do.

The contract

A put option gives the holder the right, but not the obligation, to dispose of a defined number of shares at a fixed strike price on or before a defined expiry date. The holder pays a premium upfront. The writer of the put collects the premium and takes on the obligation to take delivery of the shares at the strike if the holder exercises.

The two legitimate uses

• Hedging. A long-term holder of a Top 40 share, say a R5 million position in Sasol, can pay a premium for a put with a strike 10% below the current price. If Sasol falls 30%, the rise in the put's value partly offsets the loss on the share. The premium is the cost of the insurance. This is the cleanest, most defensible institutional use.
• Defined-risk speculation. A trader expecting a particular share or index to fall can express that view with a put. The maximum loss is the premium paid, which is known up front. This is honest about the worst case in a way that short-selling the share directly is not.

How a put actually behaves

• If the share falls well below the strike by expiry, the put has intrinsic value equal to the difference, multiplied by the contract size.
• If the share is at or above the strike at expiry, the put has no intrinsic value and the premium is forfeit.
• Between now and expiry, the put's price is driven by the same three forces that drive a call, direction, time decay and implied volatility, but with the direction reversed.

The volatility quirk no one mentions

Puts on equity indices are systematically more expensive than calls on the same indices at equivalent distances from the spot price. This is the well-documented "volatility skew" or "smirk", and it exists because institutions are persistent buyers of downside protection. The practical implication for retail: speculative puts on a stable Top 40 share are structurally more expensive than the equivalent calls, which means the breakeven move required is larger.

What honest disclosure looks like

• The full premium can be lost.
• Time decay accelerates in the final month and is the dominant force in short-dated contracts.
• A correct directional view can still lose money if implied volatility falls before the share does.
• Writing puts, taking the other side, which the marketing presents as "getting paid to buy shares at a discount", carries materially larger downside than buying them, and is not a beginner strategy regardless of how it is packaged.

Companion reading: what is a call option?, what is a warrant?, and how risky is options trading?