A cash account makes the words “cash-secured put” literal: the full strike value must be there, uninvested, before the broker will accept the order.

A margin account will let you sell the same put with a fraction of that. The payoff diagram is identical, the greeks are identical, and the position is not the same trade at all.

The two requirements

Margin requirements are formula-driven and vary by broker, but the shape is roughly: a percentage of the underlying's value adjusted for how far out of the money the strike is, with a floor. The practical effect is that a put needing $9,500 in cash might need $1,900 on margin.

Critically, the margin requirement moves. As the stock falls toward your strike, the requirement rises — so the position demands more capital at exactly the moment your account can least spare it.

The cash column never moves. That is not a limitation — it is the property that makes the position survivable.

What a cash account costs you

It is not free, and the honest version includes these:

Settlement rules. Proceeds from a closing trade take a day to settle before the cash can be reused. In practice this means you cannot always redeploy immediately, which blunts the close-early-and-redeploy argument somewhat.

Fewer positions. The strategy is capital-hungry and a cash account gives you no relief.

Spreads may be restricted. Some brokers require margin approval for multi-leg positions even when they are defined-risk.

The argument for cash anyway

The constraint is doing something valuable. A cash account makes it impossible to take a position you cannot honour, which removes the single most damaging error available in this strategy.

It also enforces the discipline that makes the wheel coherent: if you cannot secure it, you cannot sell it, so every put you write is genuinely one you could take delivery on. The plan for the bad case remains real rather than theoretical.

Traders who blow up selling puts almost never do it because they picked bad strikes. They do it because they sold more contracts than they could cover, and the margin account let them.

The middle position

A reasonable compromise for an experienced trader: hold a margin account for its flexibility — spreads, settlement, occasional adjustment room — but size every position as though it were a cash account.

That means computing your own capital requirement as strike × 100 × contracts and never letting the total exceed your cash, regardless of what buying power says. You get the operational conveniences and keep the constraint that matters.

It requires discipline that the cash account would have enforced for you, which is precisely why beginners are usually better served by the cash account.

A note on IRAs

Retirement accounts cannot use margin borrowing, so a wheel in an IRA is cash-secured by construction. That is one of the underappreciated reasons the strategy behaves well there — the account structure enforces the sizing discipline automatically.

What can go wrong

Treating buying power as the limit. It is the broker's limit, not yours.

Forgetting the requirement rises. More capital demanded exactly when the position is going wrong.

Calling a margin position “cash-secured”. The name is a description of collateral, not of the payoff shape.

Ignoring settlement in a cash account. It genuinely slows redeployment.