Offer your thoughts or opinion on the input financial query or topic using your financial background.

How do you calculate the rate of return (ROR) when buying and selling put options?
What Jaydles said. I think of each strategy in terms of Capital at Risk (CaR). It's a good thing to know when considering any position. And then conveniently, the return is always profit / CaR. With covered calls it's pretty easy. Pay $1000 for stock, receive $80 in premium, net CaR is $920.  If you own the stock and write calls many times (that expire worthless, or you that you buy back), there are two measurements to consider. First, treat every covered call as a buy-write. Even if you already own the stock, disregard the real cost basis, and calculate from the moment you write the call, using the stock price at that time. The second measure is more complicated, but involves using something like the XIRR function in a spreadsheet. This tracks the series as a whole, even accounting for times where there is no written call outstanding. For the written put, even though your broker may only require 30% collateral in a margin account, mentally treat them as cash-secured. Strike less premium is your true CaR. If the stock goes to zero by expiration, that's what you're on the hook for. You could just compute based on the 30% collateral required, but in my view that confuses cash/collateral needs with true risk. Note: a written put is exactly identical to a covered call at the same strike. If you tend to favor puts over CCs, ask yourself why. Just like a loaded gun, leverage isn't inherently bad, but you sure want to know when you're using it.