Darrin Johnson On Flirting With Models

Independently Shorting Volatility with Darrin Johnson (Podcast)
Corey Hoffstein’s Flirting With Models

Darrin Johnson is an options trader and the first independent trader Corey’s had on the pod. Considering Corey’s show focuses on institutional and cutting edge investment professionals, it says a lot that he had Darrin on the show. I’m not surprised, I’ve been following Darrin on Twitter for years and impressed by his understanding of options trading. I have always believed that option trading is an apprentice activity. I cannot imagine how difficult it would be to learn the game with the guidance of masters. Darrin has managed to cobble together that guidance from a variety of sources including Euan Sinclair’s books, Twitter, hiring grad students to walk him through the academic math, running countless simulations, and detailed reconstructions of financial products.

Here are some of my favorite aspects and insights from the interview (with my commentary):

• Darrin’s entrepreneurial path before he even found his way to trading is worthy of an interview of its own.
• The importance of building sims instead of backtesting as a way to get more samples. For those of us who trade for firms, we benefit from the collective osmosis of many traders discussing trades and situations in detail. All those morning huddles and afternoon meetings help us build a mental library of counterfactuals. Darrin did the next best thing…build simulations, knowing that a backtest is a single version of what could happen. This is crucial to get a fingertip feel for how positions behave.
• The idea of pricing out financial products to the penny. Darrin called it “back-office” kinda stuff that retail traders don’t do. Corey said he does this too. This is exactly what you do at a mm/arb shop. As a clerk I remember building giant spreadsheets to price fair value for ETFs. This is not optional work. You will use those skills to attack new products and understand the frictions to arbitrage.
• At around the 40:00 minute mark Darrin explains why he concentrates his selling on at-the-money or meaty options not the wings. He makes the correct insight: when you sell tails, you need to capture the entire premium. The hit ratio of selling tails is high but when you lose you lose many multiples of the premium. If you fail to collect the full premium, it will not make up for the losing trades. The difficulty of selling tails is even trickier yet. Darrin explains how betting against longshots leaves you uncertain if you have an edge in the first place. In my words: good luck differentiating between a 50-1 shot vs a 100-1 shot. That’s the difference of 1 probability point but it’s massive in payoff space. I discuss further in Tails Explained.
• Here’s a more subtle insight from the interview. Darrin tries to find the structure that has the best payoff to his vol forecasts or thesis. Notice the subtext. If there’s a “best” there must be a “worst”. This is the basis of relative value trading — buy the best payoff and sell the worst payoff contingent on the vol forecast coming true. For example, if you thought skew was cheap in the oil complex compared to macro backdrop, you could buy the cheapest puts across the oil and products suite. You could buy some ratio of oil puts and selling RBOB or HO puts depending on how how you think the macro stress plays out. Now you might want to be outright long the vol forecast coming true so you might not want to turn this into a basis trade (the advantage of a basis style trade is you can likely do it bigger). Or you could choose to buy oil puts and say sell puts on an equity index where the stress has been priced in. Because you’d be taking an even larger basis risk than staying within the oil complex, you would size the trade smaller than the oil basis trade, but perhaps larger than an outright long oil vol position. The point is there is a lot of creativity on trade expression that balances edge and basis risk.

Since the interview was so good, it got passed around quite a bit on Twitter. In one of the ensuing discussions, I offered my down-to-the-studs view of what options trading really is:

There’s nothing magical about options trading. Paraphrasing Darrin, the intellectuals who are drawn to it prolly need a more blue collar view. Step back and think about what the market needs. What risks doesn’t it want to hold? Obsess over the who and why, not moments [of a distribution]… For years the “job to be done” in vol was be willing to pay theta The marketplace was bidding for that role and vol folks that filled it did well. The market “bids” for different roles all the time in vol-land and the job of a vol trader is to fill it. Simple not easy.

@TheSpeculator0, who trades for a firm, astutely observes: It’s not easy to catch the regime change that switches up the roles.

My response:

That’s why risk management is key. The nature of market-making, even if you don’t explicitly have that title, is you lose on the regime change. So you adjust and hope the next regime lasts long enough to pay you for the [money-losing] transitions.

If you want a fuller discussion for the raison d’etre of vol trading, you probably won’t do better than Corey’s podcast with QVR’s Benn Eifert who describes the job as “bringing balance to the force”. I took full notes for you…Flirting With Models: Benn Eifert (Link)

If you use options to hedge or invest, check out the moontower.ai option trading analytics platform