Sell to Open vs Buy to Close: Option Orders for the Wheel
Every options order ticket asks the same question before anything else: buy to open, sell to open, buy to close, or sell to close? Pick the wrong one and you can end up long an option you meant to sell, or open a new position when you meant to exit. The Wheel strategy only needs two of the four: sell to open to start each cash-secured put or covered call, and buy to close when you want out early or want to roll. This page explains all four, shows which one to use at each step of the Wheel, and walks through the fields on a typical order ticket.
All prices and premiums below are hypothetical and rounded for easy math. They are not quotes, live prices, or typical results.
The four option order actions in one table
"Open" means the order creates a new position. "Close" means it exits a position you already have. "Buy" and "sell" tell you which side you end up on.
| Action | What it does | Cash flow | Used in the Wheel? |
|---|---|---|---|
| Sell to open (STO) | Starts a new short option. You take on the obligation. | You receive premium | Yes: every new put and every new covered call |
| Buy to close (BTC) | Exits a short option you sold earlier. The obligation goes away. | You pay premium | Yes: early exits and the first half of a roll |
| Buy to open (BTO) | Starts a new long option. You own the right. | You pay premium | Not in the basic Wheel |
| Sell to close (STC) | Exits a long option you bought earlier. | You receive premium | Not in the basic Wheel |
The easy way to remember it: a Wheel seller opens by selling and closes by buying. If your ticket says "buy to open" or "sell to close" while you are running the Wheel, stop and check what you are doing.
Which order to use at each step of the Wheel
- Start with a cash-secured put: sell to open one put per 100 shares you are willing to buy, with strike × 100 in cash set aside. Mechanics are on cash-secured puts explained.
- Put winning early? Buy to close the same put (same strike, same expiration) to lock in the profit and free the cash. Or let it expire and keep the full credit.
- Put assigned? No order needed. You now own 100 shares at the strike. See what happens when options are assigned.
- Sell a covered call: sell to open one call against each 100 shares you own. Mechanics are on covered calls explained.
- Call winning early or want to keep the shares? Buy to close the call.
- Rolling? That is a buy to close on the current option plus a sell to open on the new one, often sent together as one two-leg order. Details on rolling options in the Wheel.
Filling out the order ticket, field by field
Brokers lay their screens out differently, so check your own broker's help pages for exact menus. The fields themselves are almost always the same:
- Underlying symbol: the stock or ETF the option is on.
- Action: sell to open, buy to close, and so on. This is the field that causes most beginner mistakes.
- Quantity: number of contracts. One standard equity contract usually covers 100 shares, so 2 contracts means 200 shares of obligation.
- Expiration date and strike price.
- Put or call. The Wheel's first leg is a put; the second leg is a call.
- Order type: limit or market. Use a limit for options in most cases (more below).
- Limit price: per share, not per contract. A $1.20 limit means $120 per contract before fees.
- Time in force: usually "day" (cancels at the close if unfilled) or "good till canceled."
Before you submit, most brokers show a preview with the estimated credit or debit and the buying power the trade will use. For a cash-secured put, that buying power should be close to strike × 100 per contract, less the premium in some accounts. If the preview shows a debit when you expected a credit, you probably picked buy instead of sell.
You will also need options trading approval on the account. Brokers grant it in levels, and the level that allows covered calls and cash-secured puts is usually one of the lower ones. Each broker decides its own levels.
Limit orders and the midpoint
Options often have a visible gap between the bid (what buyers will pay) and the ask (what sellers want). A market order fills at whatever is available, which on a thin option can cost you a meaningful slice of the premium. A limit order sets the worst price you accept.
A $45 put on illustrative stock XYZ shows a bid of $1.10 and an ask of $1.30. The midpoint is $1.20.
You enter sell to open, 1 contract, $45 put, limit $1.20, day. If it fills, you receive about $120 before fees and the broker sets aside about $4,500 as cash collateral. If it does not fill after a few minutes, some sellers lower the limit by a cent or two at a time. A market order might have filled near the $1.10 bid, about $10 less per contract.
Two weeks later the stock has risen and the same put shows bid $0.30, ask $0.40. You enter buy to close, 1 contract, $45 put, limit $0.35. If it fills, you pay about $35, keep about $85 of the original $120 credit before fees, and your $4,500 is free for the next trade. When to do this is covered on when to close a covered call or put.
Common order mistakes (and how to catch them)
- Buy to open instead of sell to open. You pay premium instead of collecting it and end up long the option. The preview will show a debit. Cancel or, if it already filled, sell to close it.
- Sell to open instead of buy to close. You wanted to exit a short call but opened a second one. On a call with no extra shares behind it, that can be a naked call, which carries much larger risk. Many brokers block it at lower approval levels, but do not rely on that.
- Wrong expiration or strike on the closing order. A buy to close must match the exact contract you are short. Pick it from your positions list when your broker allows that.
- Per-share vs per-contract price. Entering $120 instead of $1.20 as a limit is an expensive typo on a buy order. Brokers often warn you, but read the preview.
- Too many contracts. Quantity is contracts, not shares. Ten contracts on a $45 put is roughly $45,000 of potential stock purchase.
Letting it expire vs buying to close
You do not have to close every short option. An out-of-the-money option at expiration usually expires worthless, and you keep the whole premium without another order or fee. Reasons sellers buy to close anyway:
- Most of the premium is already captured and the remaining few cents are not worth the risk of a late move.
- They want the cash or shares free to start the next cycle sooner.
- An earnings date or ex-dividend date is coming. See the Wheel around earnings and ex-dividend early assignment.
- They want to roll instead of being assigned.
Run any candidate trade through the free Wheel calculator to see the return on capital before you send the order, and track your adjusted basis with the Wheel cost basis calculator after assignment.
For a step-by-step system covering strike choice, sizing and every decision after the order fills, read Spin the Wheel, Cash the Checks by Logan Sterling (Kindle eBook).
Related reading on this site
- Cash-secured puts explained: the first leg of the Wheel.
- Covered calls explained: the second leg.
- Rolling options in the Wheel: buy to close plus sell to open in one move.
- When to close a covered call or put: timing your buy to close.
- What happens when options are assigned.
- Wheel strategy glossary: plain definitions of the terms on this page.
FAQ
What does sell to open mean?
Sell to open starts a new short option position. You receive the premium up front and take on the obligation that comes with the contract: for a put, possibly buying 100 shares at the strike; for a call, possibly selling 100 shares at the strike. In the Wheel, every new cash-secured put and every new covered call is a sell to open order.
What is the difference between sell to open and sell to close?
Sell to open creates a new short position you did not have before. Sell to close exits an option you already own (a long option you bought earlier). Wheel sellers almost always use sell to open; sell to close is for people who bought options and now want out.
What is the difference between buy to open and buy to close?
Buy to open creates a new long option position, so you pay premium and own the right. Buy to close exits a short option you sold earlier, so you pay to remove the obligation. A Wheel seller uses buy to close to take profits early, cut a losing short option, or as the first half of a roll.
Is a covered call sell to open?
Yes. You open a covered call by selling to open one call contract for every 100 shares you already own. If you later want out before expiration, you buy to close that same call.
Is a cash-secured put sell to open?
Yes. A cash-secured put is a sell to open put order with enough cash set aside to buy 100 shares at the strike if you are assigned. Strike times 100 is the cash a broker typically holds per contract.
Do I have to buy to close before expiration?
No. If the short option expires out of the money it usually expires worthless and you keep the full premium with no closing order. If it finishes in the money you can expect assignment. Many sellers still buy to close early to lock in most of the profit or to avoid assignment, especially when only a few cents of premium remain.
Should I use a market or limit order for options?
Most option sellers use limit orders. Option bid-ask spreads can be wide, and a market order can fill at a poor price. A common habit is to start a limit near the midpoint between the bid and the ask and adjust in small steps if it does not fill.
Educational only, not financial advice. Options involve risk. Examples on this page are for illustration only and are not recommendations to buy, sell or hold any security or option. Broker screens, approval levels and fees vary; check your own broker's documentation.