Annualized Return on a Cash-Secured Put
Annualizing the return on a cash-secured put lets you compare trades of different lengths — but the number it produces is a ceiling, not a forecast.
When traders sell cash-secured puts, they often want a single figure that says “how good was this trade?” The honest version of that figure has two parts: the return on the one trade itself, and an annualized version that puts trades of different durations on the same footing. Both are easy to compute. The trap is treating the annualized number as a promise.
Step 1: the static return on one trade
The static return is the premium you collected divided by the cash you had to reserve as collateral. For a cash-secured put, the collateral is the strike price times 100 (the cost of buying 100 shares if assigned).
Static return = premium received ÷ (strike × 100)
Step 2: annualize it
A trade that earns 2 percent over 35 days is not the same as one that earns 2 percent over 200 days. To compare them, scale the static return up to a full year by multiplying by 365 divided by the number of days to expiration.
Annualized return = static return × (365 ÷ days to expiration)
A worked example
Sell a 100-strike put for 2.00 (200 dollars) with 35 days to expiration:
- Collateral = 100 × 100 = 10,000 dollars.
- Static return = 200 ÷ 10,000 = 2 percent over 35 days.
- Annualized = 2 percent × (365 ÷ 35) ≈ 20.9 percent.
That 20.9 percent is what the trade would return in a year if you could repeat it over and over at the same terms with no interruptions.
The annualized figure is a ceiling, not a prediction. It assumes you can re-sell an equally attractive put the instant each one expires, all year, with no losing trades. Reality includes assignments, drawdowns, stretches where no decent premium is available, and periods when your collateral is tied up in a stock that fell. A single 35-day cycle annualized to 20.9 percent tells you the pace of that one trade — it does not tell you what a year of trading will actually deliver.
What the headline number leaves out
- Assignment risk. The formula counts the premium but ignores what happens if the stock falls well below the strike and you are assigned at a loss. A string of premiums can be erased by one bad assignment.
- Drawdowns and idle stretches. The math assumes continuous, uninterrupted compounding. Real schedules have gaps.
- A realistic benchmark. The Cboe S&P 500 PutWrite Index (Cboe PUT index) tracks a disciplined, mechanical put-writing strategy on a broad index. Over the long run it has tended to return roughly 8 to 10 percent a year, with real drawdowns in stressed markets. That is a far more grounded expectation for systematic put-writing than any single annualized cycle.
Return on collateral vs. return on capital
The static-return formula above is a return on collateral — premium against the cash reserved for that specific put. Your return on capital is broader: it measures performance against your entire account, including cash that is idle between trades and positions that are not currently working. Return on collateral always looks higher because it ignores the capital sitting on the sidelines. When comparing a put-writing program to simply owning an index, return on capital is the fairer comparison.
The small bonus on reserved cash
One genuine plus: the cash you set aside as collateral does not have to sit dead. In many brokerage accounts it can earn a money-market or sweep yield while it waits to be called on. That yield stacks on top of the option premium, modestly improving the real return on the collateral — a detail the basic formula leaves out.
Doing the math without doing the math
The cash-secured-put calculator in the toolkit runs exactly these steps — static return, annualized return, and the collateral figure — so you can compare candidate trades on a like-for-like basis. See the tools section for it. For the underlying mechanics of the option being sold, review calls vs. puts.
Educational only — not investment advice. Options involve a substantial risk of loss and are not suitable for every investor.