Lesson 2 of 8 · Beginner

Cash-Secured Puts explained

~10 minutes reading · 6 quiz questions at end

A cash-secured put (CSP) is the first leg of the wheel. Understanding it mechanically is essential — everything else in this course builds on it. Let's break it down completely.

What a put option actually is

A put option is a contract giving its buyer the right (but not the obligation) to sell 100 shares of a specific stock to the option seller at a specific price (the strike) on or before a specific date (the expiration). When you sell a put, you're on the other side of that contract — you have the obligation to buy the shares at the strike if the buyer chooses to exercise.

Why would someone buy a put? Because they want protection against a stock falling, or they're speculating that it will fall. Why would you sell one? Because you're getting paid up front for taking on that potential obligation.

What "cash-secured" means

"Cash-secured" means you have (strike × 100) in cash sitting in your account, uninvested, ready to buy the shares if you're assigned. It's not a fancy technique — it's just showing your broker (and yourself) that you can honor the obligation.

Compare with a naked put: same trade, but you don't have the cash reserved. If assigned and you can't cover, your broker forces the trade at market prices or margin-calls you. Cash-secured is safer, simpler, and required for beginners at most brokers.

Rule of thumb: if you're a new options seller, only sell cash-secured puts. Never sell naked puts until you've done at least 100 CSP cycles successfully and understand every mechanic below.

The four numbers that define every CSP

Strike price. The price at which you'll buy the shares if assigned. You choose this.
Expiration date. When the option contract expires. You choose this too. Usually 21-45 days out.
Premium. The cash you collect for selling the put. Determined by the market (based on strike, expiration, current spot, and implied volatility).
Delta. A rough measure of assignment probability. A 0.30 delta put has roughly a 30% chance of being assigned by expiration.

You pick the strike and expiration; the market gives you the premium; delta is implied by all four.

Worked example on SPY

Setup

SPY spot: $520
Chosen strike: $505 (2.9% below spot, out of the money)
Chosen expiration: 30 days from now
Delta of the $505 put: 0.30 (roughly 30% assignment probability)
Market premium for this put: $2.30/share = $230 per contract (per 100 shares)

You sell 1 contract. Here's what happens:

Cash collected: $230 (premium, immediately deposited to your account)
Cash locked as collateral: $50,500 (= 100 × $505 strike, held aside until expiration or assignment)
Your annualized yield if the CSP expires worthless: ($230 / $50,500) × (365 / 30) = 5.5% APR

What happens at expiration?

Three cases:

Case 1: SPY expires above $505 (~70% probability)

The option expires worthless. Nobody exercises — why would they, they can sell at market for more than $505. You keep the $230 premium AND the $50,500 collateral. You can immediately sell another CSP for another 30-day cycle. Ideal outcome.

Case 2: SPY expires below $505 (~30% probability)

You're assigned. Your $50,500 buys 100 shares at $505. Your effective cost basis is $505 − $2.30 = $502.70/share. If SPY closed at $500, you own shares worth $50,000 that cost you (net) $50,270. You're down $270 on paper, but you've now started Leg 2 of the wheel.

Case 3: SPY sits exactly at $505 (rare)

Technically your obligation triggers. Practically, this is very unusual. Assume you're assigned in this case — treat it like Case 2.

Why some strikes are "richer" than others

If you'd sold the $500 strike instead of $505, you'd have collected less premium (maybe $1.90) because the strike is further from spot (lower delta ≈ 0.25). If you'd sold the $515 strike (closer to spot), you'd have collected more premium (maybe $4.10) because the strike is closer to being ITM (higher delta ≈ 0.42). Strike selection is a trade-off:

Higher strike (closer to spot): more premium, more assignment probability, more capital tied up.
Lower strike (further from spot): less premium, less assignment probability, but larger capital reserve compared to premium collected.

Where to see this live

Open the Cash-Secured Put Calculator, type "SPY," and load the chain. Look at the various 30-DTE strikes near spot. Notice how premium, delta, and assignment probability all move together as you scan up and down the strike ladder. Then check the IV Rank badge at the top — if IVR is low, all these premiums will be thin; if IVR is high, all will be rich.

Take the quiz below to lock in the CSP fundamentals, then continue to Lesson 3 to learn what happens when you get assigned.