People, people! Let’s all take a deep breath here and remember that Delta is the amount of stock required to hedge an OPTION position, not vice versa. One inverses the equation to understand how many options are needed to hedge one’s stock position. Why? Because the whole shebang was initially driven by options market makers, who write options for a living. What sane person who seeks to make money for their clients would be short volatility on purpose, and consistently? (No jokes about long bond managers, OK.) So let’s say I’m an Options market maker. About 90% of the time, I’m writing options, so I have a massive book of short vol positions, and thus am incredibly sensitive to the movements of the underlyings. I need a way to hedge the risk of being called in and not being able to pay for it, so Delta tells me how much stock I need to buy or sell in order that I don’t get squashed, and Gamma tells me how fast I need to be re-hedging. Think about this from the market makers’ perspective: if they have written a put at a particular price, they’re on the hook to buy at, say, $20. If the stock tanks at goes to $3, clearly they should have shorted an equivalent amount such that figuring in the premium, they make $.50 in any event.
If I want to use the same equation to create synthetic stops on my long cash or short cash positions, I can go and do that, and even borrow the market makers’ terminology, but the equation remains the same. Can we all go back to being friends now?