It's a bunch of mumbo jumbo from someone that takes the academic side of finance too seriously (LTCM anyone?).
In plain English: Options are basically a contract, with a time limit, that states the holder can buy a certain amount of stock at a certain price. "Options dealers" are the people who wrote the contract and sold it to another party. They are on the "hook" for fulfilling the terms, if the buying party wishes to "exercise" an option and buy their promised stock at the promised price.
Options dealers are automatically "short" all of the contracts they sell, because that's literally the definition of "shorting" -- selling something you don't own. Options dealers technically do not own the stock they're promising to sell to the buyer, but will have to once the buyer "exercises" the options contract.
Delta is basically the difference in velocity of the price of the options contract vs. the price of the stock it's representing. So, if the option is selling for $10, and has a delta of 1 (100%), then a $5 increase in the stock price will increase the option contracts price by $5 to $15. If the delta is 0 (0%), the price of the contract will not change.
Actually, I was wrong. The GP was correct to use the vocabulary he did -- because what I wrote isn't even the full explanation I was planning. However, three paragraphs in, I realized it would take much more to completely explain it.
Basically, options dealers hedge by buying the stock they issue options contracts for, and this can cause the price to move up.
> It's a bunch of mumbo jumbo from someone that takes the academic side of finance too seriously (LTCM anyone?).
Because they used standard, well-defined terms from that particular field? "Gamma" is further from mumbo-jumbo than 90% of computer programming vocabulary - it has a clear definition and everyone in the field understands exactly the same thing by it.
I am one of the best options traders in the world.
Options dealers don't necessarily sell options. They can also buy them. And "writing" an option means to sell it, so "wrote the contract and sold it" is redundant.
Options dealers are not automatically short all of the contracts that they sell. They may already have a long position in that option contract, in which case their sale is a closing sale. Also, I think you may be a bit confused...a short sale of options is not determined based on one's position in the underlying; you can be short an option and long the stock at the same time (for example, an overwrite is a sale of upside calls by someone who is already long the stock).
Delta is the first-order change of the option contract value, with respect to a unit change in the underlying price. I wouldn't refer to it at "velocity" because while I understand what you are intending to communicate (it is a rate), there is another options Greek called "speed," which is the change in gamma with respect to the underlying price. Wikipedia has a really nice description of the various options Greeks. For the truly curious, Sheldon Natenberg wrote a nice book called "Options Volatility and Pricing" that explains the Greeks better than I or Wikipedia can.
Options dealers who are short gamma will hedge by buying stock as it goes up, and selling stock as it goes down. Their demand for (or supply of) the underlying stock will impact the underlying price in a way that pushes the price in whatever direction it has already started to move.
In defense of my word choice: theory and practice are not mutually exclusive. If you want to be excellent at something, you should aim to learn both. BTW I have never taken an academic course on options or finance.
A comment I'm sure you expected you'd get on this forum: you're gonna have to elaborate a bit on/defend a bit that opening line there about being one of the best options traders in the world.
Oh yeah the explanation was much better, but this is one of those cases where the claim of being the best options trader makes the explanation less credible than if they hadn't opened with that and ended with "i've never taken a course" etc. Without it, they're citing the book and wikipedia, but with those statements, they're citing their own expertise and raising questions over their judgement on what sources they are drawing from.
I don't think that would merit the title - when you're talking about small niche situations it's harder to make the case that fantastic results are a result of skill versus luck + selection bias, and even if it's skill then you're not one of the best options traders, you are one of the best traders in that niche.
> someone that takes the academic side of finance too seriously
You know, that's totally fine with me. It's good to have those people around. As I learn more I'll be able to decide for myself what I think of that perspective. Your side is great too.
If you’re interested in learning more about finance, I recommend subscribing to Money Stuff (free daily finance newsletter). Matt Levine does a great job of explaining concepts like these to a layperson and I love his sense of humor.
Thank you for the recommendation. I'm already pretty deep in to a lot of economics and finance newsletters and podcasts. I am also familiar with Matt's work, though not a direct follower. I hear great things though!
