WhitmanTrading

The Cash-Secured Put, and When It Makes Sense

A cash-secured put is selling a put option while holding enough cash to buy the shares if assigned. The premium is kept whatever happens, and the seller takes on an obligation to buy at the strike price if the share falls below it.

How it works

The underlying price swept from low to high above, with the payoff of a sold put below. The headline on the chart reads: Selling a put with the cash set aside to buy.
Selling a put with the cash set aside to buy. Illustrative chart - not real market data.

You sell someone the right to sell you shares at a fixed price. They pay you a premium. If the share falls below that strike, you buy — at the strike, regardless of where the market is.

“Cash-secured” means the money to buy is set aside and not used for anything else. That is what separates this from selling a put on margin, where the obligation exists without the funds behind it.

The underlying swept from low to high above, with the sold-put payoff and the plain share payoff drawn together below. The headline on the chart reads: You are paid to accept an obligation to buy lower.
You are paid to accept an obligation to buy lower. Illustrative chart - not real market data.

The payoff below the strike is the share’s payoff, shifted up by the premium. Above the strike it is flat. You have taken on most of the downside and none of the upside.

The numbers

Strike 100, premium 4:

Maximum gain +4 — the premium, reached at 100 and never exceeded
Breakeven 96 — the strike minus the premium
Below 96 losing, and the loss grows as the share falls
Worst case the share goes to zero; you paid 100 and received 4

The maximum loss is large and it is bounded, unlike a naked call. It is the strike minus the premium, per share, and the cash set aside is exactly what covers it.

A 72-bar candlestick section of the shared price history. The headline on the chart reads: The cash is reserved, which is what makes it covered.
The cash is reserved, which is what makes it covered. Illustrative chart - not real market data.

That reserved cash is the strategy’s real constraint. One contract on a $100 share ties up $10,000 whether or not anything happens, and the return has to be judged against that committed capital rather than against the premium alone.

In practice: what makes it work

The underlying swept from low to high above, with a theta curve below. The headline on the chart reads: Time works for the seller of the contract.
Time works for the seller of the contract. Illustrative chart - not real market data.

Decay works for you here. As the seller you collect it: half the days gone leaves 70% of the extrinsic value, so the second half of the period returns more than the first.

A flat, quiet stretch of the long price series with an extrinsic-value curve decaying below it. The headline on the chart reads: And the premium is earned by waiting.
And the premium is earned by waiting. Illustrative chart - not real market data.
A sideways, range-bound candlestick series. The headline on the chart reads: It pays best when nothing much happens.
It pays best when nothing much happens. Illustrative chart - not real market data.

The ideal outcome is a flat or slightly rising market. The put expires worthless, the premium is kept, the cash is released, and it can be done again.

A declining stretch of the long price series. The headline on the chart reads: If it falls through the strike, you own the shares.
If it falls through the strike, you own the shares. Illustrative chart - not real market data.

The other outcome is owning the shares, at the strike, having collected the premium. Whether that is good or bad depends entirely on whether you wanted them.

A long-horizon candlestick view of the same price series. The headline on the chart reads: Only sell it on something you wanted to own anyway.
Only sell it on something you wanted to own anyway. Illustrative chart - not real market data.

Which is the precondition, and it is the whole thing. Sold on a holding you would be content to own at that price, this is a way of being paid to wait for a better entry. Sold on something you picked because the premium looked good, it is a way of acquiring exactly the positions you would otherwise have avoided.

What it is not

It is not free income. The premium is payment for an obligation, and the obligation is real.

It is not the same as a limit order. A limit order to buy at 96 costs nothing and can be cancelled. This collects 4 and cannot be withdrawn — and in exchange, if the share rises, the limit order gets nothing while this keeps the premium.

It is not lower risk than owning the shares. The downside below the strike is the share’s downside minus the premium, and the upside is gone entirely. It is a different distribution, not a smaller one.

And it is not a strategy for a stock you dislike. The premium on a falling company is high because the market expects it to keep falling, and being paid to catch it does not change what you caught.

When it fails

A declining candlestick series. The headline on the chart reads: In a real decline you buy all the way down.
In a real decline you buy all the way down. Illustrative chart - not real market data.

In a genuine decline you are assigned near the top of it. The share falls through your strike, you buy at the strike, and it keeps falling. The premium collected is small relief against a large move.

And the same conditions that produce the decline produce more premium, which encourages selling another one lower. That sequence — assigned, sell again, assigned again — is how a modest position becomes a large one during the worst possible stretch.

A candlestick chart of the site's shared price history, annotated with the round-trip cost. The headline on the chart reads: And the round trip on the shares is 2% of a bar.
And the round trip on the shares is 2% of a bar. Illustrative chart - not real market data.

The third failure is capital efficiency measured wrongly. A 4-point premium on $10,000 of reserved cash is a return on $10,000, not on 4, and quoting it any other way overstates it substantially.

A fourth is rolling to avoid assignment. Buying back the put and selling a lower one postpones the outcome, pays two spreads, and works until the decline outruns the rolling — at which point the position is larger and lower than it started.

And a fifth is selling too many contracts. The obligation is per contract and it is not obvious from the premium: five contracts on a $100 share is a $50,000 commitment, which is a much larger position than the collected premium makes it feel.

A sixth is selling through an earnings release. The premium is elevated precisely because a large move is expected, so the extra collected is payment for the risk of being assigned into exactly the result that made the share cheaper.

There is also an opportunity cost that never appears as a loss. While the cash is reserved it is doing nothing else, and in a rising market the strategy collects a small premium while the shares it was aimed at move away. That outcome is recorded as a win and is frequently the worst one available.

The original data

13 of the 24,971 videos measured for this site cover cash-secured puts, at a median of 28,103 views — a solid supply, and a topic where the framing as income substantially outnumbers the framing as an obligation.

A candlestick chart of the site's shared price history, cut short at the decision bar. The headline on the chart reads: Strike is two percent away with a week left. Roll?
Strike is two percent away with a week left. Roll? Illustrative chart - not real market data.

The test that decides whether this is a good trade takes one sentence. Would you buy this share at the strike today, in this size, if no premium were involved? If yes, being paid to wait is a reasonable arrangement. If no, the premium is compensation for a risk you had already decided not to take.

Put options is this contract seen from the buyer’s side. Covered calls is the mirror strategy on shares you already hold. And assignment is the event this whole approach is designed around.

What I actually do

The test I apply now is simple and I did not apply it at first: would I be pleased to own this at the strike, today, without the premium? If the answer is no, then I am not being paid to buy something I wanted — I am being paid to take a risk I would otherwise have declined.

— Michael Whitman

This page is educational, not financial advice. Test every idea on your own charts before risking money.