A covered call sells a call against 100 shares you own. A cash-secured put sells a put while holding enough cash to buy 100 shares at the strike. Both collect a premium in exchange for an obligation tied to a stock you are prepared to own, which is why they are the usual first step into options income. The Learn articles on the covered call and the cash-secured put give the formulas; this lesson is about the decisions around them.
The two payoffs
Take a stock at $50 with 35 days to the chosen expiry. Values are per share; one contract covers 100 shares.
| Measure | Covered call: own at 50, sell the 52 call for 0.95 | Cash-secured put: sell the 48 put for 0.90 |
|---|---|---|
| Maximum profit | 52 − 50 + 0.95 = $2.95 ($295) | $0.90 ($90) |
| Breakeven at expiry | 50 − 0.95 = $49.05 | 48 − 0.90 = $47.10 |
| Loss if the stock goes to zero | $49.05 ($4,905) | $47.10 ($4,710) |
| Capital committed | $5,000 of stock, less the $95 premium | $4,800 cash, less the $90 premium |
| Return if nothing goes wrong | 1.9% if the stock is unchanged; 5.9% if called away | 90 ÷ 4,710 = 1.9% in 35 days |
Why they are nearly the same trade
The two charts have the same shape: a flat line on the right and a sloped line on the left. That is not a coincidence. By put–call parity, owning a stock and selling a call at strike K produces, at expiry, the same payoff as selling a put at strike K and holding the cash. A covered call is therefore a short put in disguise, and a cash-secured put is a covered call that has not yet bought the shares.
Three consequences follow:
- The risk is the stock's. Both structures carry nearly the full downside of owning the shares. The premium is a cushion, not a hedge.
- Choose by circumstance, not by belief. If you already own the shares, a covered call adds the obligation to sell; if you hold cash, a cash-secured put adds the obligation to buy. Differences come from dividends (only shareholders receive them), taxes and transaction costs.
- The same rules apply. Strike, expiry and exit decisions for one translate directly to the other.
Choosing the strike and the expiry
The strike is a price decision before it is a premium decision:
- Covered call: sell a strike at which you would be content to sell the shares. A strike near 0.30 Delta, like the 52 call above (about 0.34), balances income against keeping some upside; a 0.15–0.20 Delta call keeps more upside for less premium. A strike just above clear resistance or a large call open interest level gives the price a hurdle to clear first.
- Cash-secured put: sell a strike at which you would genuinely want to buy. Placing it below support, or below the put wall where put open interest is heaviest, adds a level the price must break first. A strike you would not buy at is a sign the trade is about premium, not about the stock.
- Expiry: 30–45 days is the usual balance (lesson 2). Check the calendar: an earnings report before expiry raises the premium and the chance of a gap, and a covered call that spans an ex-dividend date can be assigned early.
- Liquidity: prefer strikes with real open interest and a bid/ask spread that is a small fraction of the price. A wide market can cost more than the edge you hope to collect.
Assignment and early exercise
Options on US stocks and ETFs are American-style: the holder may exercise on any business day. At expiry, an option that finishes at least $0.01 in the money is normally exercised automatically unless its holder instructs otherwise. Exercise notices are allocated to accounts that are short the option, so assignment is not something you choose. Holders can also act on news after the close on expiry day, so an option that closes just out of the money can still be exercised.
- Short calls and dividends. The holder of an in-the-money call gains by exercising just before the ex-dividend date when the dividend is larger than the call's remaining time value. Example: the stock is $49 the day before going ex-dividend, the dividend is $0.60, and your short 45 call trades at $4.15. Its time value is 4.15 − (49 − 45) = $0.15, well below the dividend, so assignment that evening is likely. Your shares are sold at 45 and you do not receive the dividend. If you want the dividend, buy back or roll the call before the ex-date.
- Short puts. Early assignment usually happens only when a put is deep in the money with almost no time value left. For a cash-secured put it simply brings forward a purchase you had already funded.
- After assignment. A put assignment leaves you long 100 shares at the strike, with a net cost of strike minus premium ($47.10 above). A call assignment sells your shares at the strike, so your total proceeds are the strike plus the premium ($52.95 above).
Taxes in general terms
Tax treatment depends on your country and account type, and this lesson cannot advise on it. Points worth checking with a tax adviser: whether option premiums are taxed when an option expires or is closed, or are folded into the stock's cost or sale price on assignment (the common US approach); whether frequent short-dated trades create short-term gains taxed at higher rates; whether writing in-the-money calls can affect the holding period of the shares or the treatment of their dividends; and whether loss rules such as the US wash-sale rule apply when you are assigned shares shortly after selling the same stock at a loss. Tax-advantaged accounts often allow covered calls and cash-secured puts but restrict margin.
How to apply it
- Entry. Only on a stock you are content to own (put) or to sell at the strike (call). Default to 30–45 days and about 0.30 Delta, with no earnings before expiry unless intended, and check the ex-dividend date for calls.
- Target. Buy back the option at about half the premium, or let it expire if little time is left and the stock is far from the strike.
- Stop. The stop belongs to the stock, not the option. Decide in advance the price or event (support broken, thesis changed) at which you would no longer want the shares, and close the put, or the shares and call together, if it occurs.
- Invalidation. A change in the business case, an unexpected event before expiry, or implied volatility so low that the premium no longer pays for the risk.
- When tested. For a covered call in a rally, let the shares go as planned or roll up and out for a small net cost only if you deliberately want to keep them. For a cash-secured put in a decline, accept assignment if you still want the stock, roll down and out for a net credit, or close.
In Clear Tape
Pro members can build both on any optionable stock in the strategy builder on the Options page. The covered call owns 100 shares at the current price and sells a call near 0.30 Delta; the cash-secured put sells a put near 0.30 Delta; both start from the expiry closest to 35 days, and the strike, Delta and expiry can be changed. The build shows the credit at mid and at natural prices, maximum profit and loss, breakeven, chance of profit, capital at risk and return on it (annualized), the strike's distance in expected moves, and checks such as earnings before expiry, a strike beyond the call or put wall, wide quotes or thin open interest. The fit rating marks a covered call as a good fit when options are rich, and a cash-secured put when options are rich, the price is above the put wall and not below the gamma flip, and no earnings fall before expiry. Data reflects the previous session's close; no orders are placed. See pricing.
Common mistakes
- Selling puts on a stock you would not want to own, because the premium is high.
- Selling covered calls at a strike below what you paid and then being called away at a loss.
- Forgetting the ex-dividend date and losing the dividend to early assignment.
- Treating the premium as protection: a 1.9% cushion does little against a 20% decline.
- Ignoring taxes and costs that turn a small gross return into a smaller net one.
Summary
Covered calls and cash-secured puts are two routes to the same payoff: a capped gain and nearly the full downside of the stock, softened by the premium. Choose the strike as a price you would act on, the expiry with the calendar in view, and the stop on the stock itself. Watch for dividends on short calls and remember that assignment is decided by the holder. The next lesson joins the two into a repeating cycle: the wheel.
For educational purposes only. Not investment advice.