A cash-secured put is an options strategy where you sell a put option on a stock and set aside enough cash in your brokerage account to buy 100 shares at the strike price if the buyer exercises. You collect a premium up front for taking that obligation, and you either keep the premium outright, end up buying the stock at a net discount, or close the trade early for a gain or loss. Investors use cash-secured puts to earn income on idle cash or to get paid while waiting to buy a stock they already want to own at a lower price.
How the Trade Works
When you sell (or “write”) a put, the buyer on the other side pays you a premium for the right to sell you 100 shares at the strike price any time before the contract expires. The premium lands in your account immediately. A single put at a $50 strike commits you to a potential $5,000 purchase. If the option is never exercised, your obligation ends on the expiration date.
Three things can happen between the day you sell the put and the day the contract ends. The stock stays above the strike and the option expires worthless. The stock falls below the strike and you get assigned the shares. Or you decide to close the position early by buying back the same contract on the open market.
Why the Cash Backing Matters
The defining feature of this strategy is that you hold the full purchase amount in your account the entire time the put is open. Under Regulation T, the Federal Reserve rule governing brokerage credit, a short put that isn’t cash-settled obligates you to buy the shares if assigned, and to qualify for a cash account the entire amount at risk must be held in cash or cash equivalents. Your broker multiplies the strike by 100 and locks that amount away until the position closes or expires.
That cash can’t be used for other trades while the put is open. Some brokers sweep the collateral into a money market fund or bank deposit program that pays modest interest; others leave it as a free credit balance earning little or nothing. It’s worth checking how your broker handles collateral cash before tying up a large sum.
Full cash backing is what separates this strategy from naked or margin-based put selling, where a broker lends you leverage and a sharp decline can trigger a margin call. With a cash-secured put, the worst case is defined from the start: you buy the stock at the strike price, and the premium you collected offsets part of what you paid.
When the Option Expires Worthless
If the stock closes above the strike at expiration, the put buyer has no reason to exercise. Why sell shares to you at the strike when the open market pays more? The option expires, your collateral is released, and you keep the full premium as profit. The Options Clearing Corporation automatically exercises equity options that finish in the money by at least $0.01, so if the stock closes even a penny below the strike, expect assignment unless the buyer’s broker submits a do-not-exercise instruction.
Many put sellers see a worthless expiration as the ideal outcome. You earned income without ever buying the stock, and the cash is free to deploy on another trade.
When You Get Assigned
Assignment happens when the buyer exercises and you’re the seller selected to deliver. It’s most likely when the stock trades below the strike, since the buyer profits by selling shares to you above market value. American-style options, the standard for U.S. equities, can be exercised any time before expiration, so assignment can arrive earlier than you expect. Deep in-the-money puts whose time value has mostly decayed carry the highest early-assignment risk.
Once assigned, your broker uses the segregated cash to buy 100 shares at the strike price. Settlement takes one business day under the T+1 cycle. After settlement you own the shares outright, with dividends, voting rights, and the ability to sell whenever you want.
The downside is straightforward. If the stock has fallen well below the strike, you own shares worth less than you paid. Overnight gaps are especially dangerous: a stock can drop sharply on bad earnings or unexpected news while the options market is closed, and by the time trading reopens the damage is done. The premium you collected provides a small cushion but won’t offset a large decline.
Closing or Rolling Before Expiration
You’re not locked in until expiration. You can enter a “buy to close” order at any point, buying back the same put on the open market to cancel your obligation. If the stock rose after you sold the put, the option is now cheaper and you pocket the difference. If the stock fell, closing costs you money, but it ends the trade before assignment.
Some sellers “roll” the position: buy to close the current put and simultaneously sell a new one at a different strike or a later expiration. Rolling to a lower strike reduces assignment risk; rolling to a later date collects more premium. Each leg is its own taxable event.
How Each Outcome Is Taxed
The tax treatment depends on which of the three outcomes you end up with.
If the Put Expires Worthless
The full premium is a short-term capital gain in the year the option expired, regardless of how long you held the position. Short-term capital gains are taxed as ordinary income, which for 2025 ranges from 10% to 37% depending on your taxable income. Report the transaction on Form 8949 and carry the totals to Schedule D.
If You Get Assigned
The premium isn’t taxed on its own. Instead, the IRS requires you to subtract it from the cost basis of the shares you buy. Sell a put at a $50 strike and collect $2 per share, and your adjusted basis is $48 per share. No tax is owed on the premium at that point.
The tax bill arrives when you later sell the stock. Gain or loss is measured from the adjusted $48 basis. If you sell at $55, you have a $7 per share gain. Whether it’s short-term or long-term depends on how long you hold the shares after assignment, counted from the settlement date. More than one year qualifies for long-term capital gains rates; shorter is taxed as short-term. Report the sale on Form 8949 using the adjusted basis.
If You Buy to Close Early
The difference between the premium you received and the price you paid to close is a short-term capital gain or loss, no matter how long the position was open. Commissions and fees reduce your proceeds. Report the result on Form 8949.
Watch Out for the Wash Sale Rule
The wash sale rule can create unexpected tax problems for cash-secured put sellers. If you sell a security at a loss and acquire the same or a substantially identical security within 30 days before or after the sale, the loss is disallowed. The statute specifically includes contracts or options to acquire stock in its definition of “stock or securities.”
Suppose you sell shares of a stock at a loss, then within 30 days sell a cash-secured put on that same stock. The IRS can treat the put as a contract to acquire substantially identical securities and disallow your loss. The disallowed amount gets added to the basis of the replacement position, so the deduction is deferred rather than lost forever, but it can still throw off your tax planning for the year. Track dates carefully when you’re trading both the stock and puts on the same underlying.
The Net Investment Income Tax
Higher earners face an additional 3.8% net investment income tax on capital gains from options trading. It applies when modified adjusted gross income exceeds $200,000 for single filers or $250,000 for married couples filing jointly. These thresholds are not indexed for inflation. For someone in the top ordinary bracket, a short-term gain from an expired put can be taxed at an effective rate up to 40.8%.
Corporate Actions Can Change the Contract
The standard 100-share contract size is not permanent. Stock splits, mergers, special dividends, and other corporate actions may change the shares a contract covers, the strike price, or both. After a 2-for-1 split, a single $50-strike put would typically become a put on 200 shares at a $25 strike. The economic exposure stays roughly the same, but the terms in your account look different and the cash collateral requirement adjusts accordingly. When a corporate action is announced on a stock you’ve sold puts against, check the OCC’s adjustment memo, because the new terms may no longer fit the thesis you had when you opened the trade.