Cash-Secured Put

Get paid to potentially buy stock at a discount. Outlook: neutral. Direction: credit. Risk: limited.

A cash-secured put (CSP) means selling a put while holding enough cash to buy 100 shares at the strike if assigned. You collect the premium either way. If the underlying stays above the strike, you keep the premium as pure income; if it falls below, you are put shares at the strike minus the premium, an effective buy-at-discount.

CSPs are one of the two core premium-selling strategies (alongside covered calls). Both are framed around being willing to hold the underlying, either to keep selling covered calls after assignment, or to accumulate a position at target prices.

Worked example: a stock trades at $100; you would like to own it at $95 or lower. Sell a 30-day $95-strike put for $1.20 per share ($120 credit), reserving $9,500 cash collateral. Three outcomes at expiration: (1) stock at $97 - the put expires worthless, you keep the $120 premium, the cash returns to your account, return is $120 on $9,500 in 30 days (about 1.3%). (2) stock at $94 - the put is assigned, you buy 100 shares at $95 for $9,500 cash, effective entry is $95 minus $1.20 premium = $93.80; mark-to-market is -$0.80/share but your effective cost is below the spot price you targeted. (3) stock at $85 - the put is assigned at $95, your effective cost is $93.80 but the stock is at $85, immediate mark-to-market loss is about -$8.80/share. CSPs do not protect against sharp drops below the strike.

Break-Even

Break-even = strike - premium per share. Below this level at expiration, the position is underwater.

Max Profit

Premium received x 100 x contracts, achieved if the put expires worthless (spot above strike).

Max Loss

(Strike - premium) x 100 x contracts, if the underlying goes to zero. Same downside as owning shares from the strike level.

Risk Profile

P/L curve is flat at +premium above the strike, kinked at the strike, and falls linearly with spot below the strike (matching long-stock losses from the effective entry of strike-minus-premium). The shape is identical to a covered call: capped profit, large but capped (at zero) downside. The "secured" in cash-secured-put refers to the collateral, not a guarantee that the trade pays off.

Greeks by Leg

Single short-option position with full cash collateral. Delta is positive (between 0 and +1), starting near +0.30 for a typical 30-delta OTM put and growing toward +1 as spot drops below the strike. Gamma is negative (positions worsens faster as spot falls). Theta is positive (the income source). Vega is negative: rising IV hurts the short put. Rho is small for short-dated puts. The position is synthetically equivalent to a covered call at the same strike: same max profit, same max loss, same break-even.

When to Use

• You want to buy the underlying at a level below the current spot.
• IV rank is elevated so the put premium is rich.
• You have cash on hand: the secured portion earns T-bill yield while you wait.
• You are willing to accept assignment and hold shares, not just collect premium.

IV-Rank Guidance: When to Enter

CSPs are most attractive when IV rank is above 50, which means the put premium is rich relative to the recent IV history. Elevated IV usually corresponds to broader market or single-name stress, which is exactly when "buy the dip via cash-secured puts" is most appealing. Selling CSPs into low-IV-rank conditions delivers minimal premium for substantial capital tied up, often less than what T-bills would yield. For names with regular earnings cycles, the post-earnings IV crush window is a common entry: sell the put after the IV-crush, before the news cycle settles.

Common Pitfalls

• Downside is steep if the underlying collapses; you bought shares at the strike regardless.
• Assignment happens at strike, not at the lower spot, so a sharp drop means immediate mark-to-market loss.
• Early assignment is uncommon but possible on deep-ITM puts near dividend dates (for the dividend).
• Selling too far OTM means tiny premium relative to capital tied up.

Adjustments and Roll Logic

• If the underlying rallies and the put has decayed to 50-80% of max profit, close early to free up capital for the next cycle rather than waiting for expiration.
• If the underlying drops toward the strike but you still want to own it, hold and accept assignment; the effective entry price is strike minus premium.
• If you want to avoid assignment, roll out (and possibly down) by buying back the current short put and selling a later-dated, slightly-lower-strike put for additional credit.
• If the underlying gaps below the strike on bad news and you no longer want to own it, close at a loss and re-evaluate; do not "double down" by selling more puts on a falling knife.

Frequently Asked Questions

What is the difference between a cash-secured put and a naked put?

Same risk profile, different broker requirements. A cash-secured put requires you to hold the full strike-times-100 in cash for each contract; a naked put uses portfolio margin, requiring much less capital but exposing you to margin calls if the trade goes against you. CSPs are the right structure for retail accounts; naked puts are a portfolio-margin product for traders willing to manage margin requirements actively.

How is this different from buying the stock?

CSPs deliver smaller upside than buying the stock outright (you only get the premium plus the discount-to-strike) but have a wider profit zone (any move above the break-even is profitable, not just a positive return). They also let you collect T-bill yield on the secured cash while you wait. The trade-off: if the stock rallies hard, you miss the rally; you only collect the premium.

Is this the same as "selling a put"?

Yes, "cash-secured put" is just the funded-collateral version. The trade itself is selling a put; the "cash-secured" prefix is about how the position is margined. Some platforms call this a "secured short put" or "covered put" (though the latter term is overloaded; pure naked-on-margin is just "short put").

When should I use CSPs over outright stock purchases?

Three common cases: (1) you want to be paid for waiting at a target entry price below current spot; (2) IV is elevated and the premium more than compensates for the cap on upside vs buying outright; (3) you want to systematically build a position over multiple cycles by selling CSPs and accepting assignments. The strategy fits the patient accumulator profile, not the quick-flip trader.

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