For educational purposes only; not individualized investment, legal, or tax advice. Options involve risk and may result in loss.
Direct answer
When a short equity Put is assigned, the writer must buy the contract’s deliverable at the strike price. One standard U.S. equity-option contract ordinarily covers 100 shares, but an adjusted contract may call for shares, cash, or both. Assignment performs the obligation accepted at Sell to Open; it is not a broker error.
This playbook applies as of 2026-08-22 to U.S. exchange-listed, physically settled equity options in ordinary retail cash or margin brokerage accounts. It does not cover cash-settled index options, futures options, employee options, OTC or FLEX contracts, or non-U.S. rules. Contract terms, account agreements, broker cutoffs, trading halts, and house requirements control.
The response is an account-control process: verify the notice, deliverable, strike debit, premium history, settlement, buying power, and margin; then decide whether the resulting stock still fits the portfolio. Holding, selling shares, or writing a covered Call are separate decisions. None reverses the original Put economics.
Before and after assignment
Put holders decide whether to exercise; writers cannot choose or reliably predict whether they are assigned. Standardized U.S. equity options are American-style and may be exercised on any business day through expiration. Assignment risk generally rises as a Put moves deeper in the money and expiration approaches, but any holder may submit contrary instructions. Exercise-by-exception is an OCC clearing procedure, not a guarantee of a customer’s outcome, and broker cutoffs may be earlier.
For an unadjusted contract whose deliverable is entirely shares, calculate:
- Shares on assignment:
contracts × deliverable shares - Strike debit:
strike × deliverable shares × contracts - Economic per-share entry:
strike − Put premium received per share, before fees and tax effects - Post-assignment concentration:
stock market value / account equity
The economic entry is a trade P/L reference, not necessarily the broker-displayed or tax basis. For a U.S. federal taxable account, IRS Publication 550 says that when a written Put is exercised, the premium received reduces the basis of the stock purchased. Transaction costs, wash-sale adjustments, corporate-action allocations, prior lots, and other jurisdictions or account types can change the result; consult a qualified tax adviser.
If ownership is unwanted, first confirm that assignment has not already occurred. A Buy to Close that executes while the short contract remains open removes that obligation. Rolling means closing the old Put and opening a new one; it realizes or preserves the old trade’s economics and creates a new obligation rather than erasing a loss.
Example: two 45 Puts in a $100,000 account
Sell 2 unadjusted $45 Puts for $1.20 per share. If assigned:
- Shares purchased:
2 × 100 = 200 - Strike debit:
$45 × 100 × 2 = $9,000 - Premium previously received:
$1.20 × 100 × 2 = $240 - Economic entry per share:
($9,000 − $240) / 200 = $43.80
If stock trades at $38, the economic unrealized loss is:
($43.80 − $38) × 200 = $1,160, or 1.16% of the $100,000 account before fees and tax effects.
Ten contracts would require a $45,000 strike debit and deliver 1,000 shares, a gross strike commitment equal to 45% of account equity. A trade that looks small by premium can become a concentrated stock position.
Suppose the investor keeps the 200 shares and sells 2 covered $45 Calls for $0.80. If both Calls are assigned at $45, the combined illustrative result from the original Put premium, stock, and new Call premium is:
($45 − $43.80 + $0.80) × 200 = $400
But a rally to $55 still results in delivery at $45; the upside above the Call strike is surrendered. If the stock keeps falling, $0.80 provides only limited cushioning. These figures exclude fees, interest, dividends, and taxes.
Assignment-day checklist
- Confirm the option symbol, contract count, deliverable, strike, exercise date, assignment notice, and settlement date.
- Reconcile shares, strike debit, cash balance, premium history, fees, and the broker’s displayed tax lot.
- Check buying power, excess liquidity, margin debit, house concentration limits, and whether the firm may liquidate positions.
- Reassess the issuer without using the premium or “break-even” as an anchor.
- Choose explicitly: hold the stock, sell all or part, or write Calls only at a strike where sale is acceptable.
- Record the entire Put-to-stock result; do not report the Put premium separately while ignoring stock loss.
Price can gap between assignment processing and the next available sale, and a trading halt may prevent an immediate exit. A margin-backed short Put can create a cash debit, a margin call, or liquidation pressure. Corporate actions can change the deliverable. Settlement, tax, retirement-account, and broker rules vary, so verify the current contract and account procedures before expiration.
Common misconceptions
- “Cash-secured means assignment cannot lose.” Cash funds the purchase; the shares can continue toward zero.
- “Assignment happens only at expiration.” American-style Puts may be exercised early.
- “Effective cost of $43.80 creates a price floor.” It is an accounting reference, not market support.
- “Selling a covered Call repairs the loss.” It adds premium while capping recovery above the Call strike.
- “Rolling avoids assignment for free.” The old position closes at its current value and the new one adds fresh risk.
- “One contract is always 100 shares.” Adjusted contracts may have nonstandard deliverables.