Managing the Book

Risk management is the part of this job that nobody outside of it ever gets right in the movies. In movies, risk is dramatic — the trader staring at a red screen, music swelling, some executive bursting through the door. In reality, risk management is mostly administrative. Quiet. Boring in the best possible way.

The goal is not to avoid being wrong. You will be wrong constantly. The goal is to make sure that when you're wrong, you're wrong in a way that doesn't end your ability to participate tomorrow.

That sounds obvious when I write it down. It is not obvious when you're sitting in a position that's moving against you and you have strong views about why it shouldn't be.

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I manage what we call a book. It's a portfolio of positions across a set of names — some long, some short, some more complex than that. At any given moment I know my gross exposure, my net exposure, my vol profile, how much I'd lose if this sector moved against me by ten percent, and what single-name concentration looks like as a share of the total.

I know all of that. Not because I'm smart, but because I built the habit of knowing it before I do anything else in the morning.

The traders who blow up — and I've watched several over the years, from a safe distance — almost never blow up because they made one catastrophically bad call. They blow up incrementally. A series of small decisions, each individually defensible, that accumulate into something indefensible.

Usually what happens is that the position gets bigger gradually. You're down a little, you add because you have conviction. You're down more, you add again because the thesis hasn't changed. The thesis hasn't changed but the position size has and somewhere in there you crossed the line between "having a view" and "needing to be right."

Needing to be right is a different psychological state than having a view. The decisions you make from that state are different. Worse, mostly.

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I heard something once that I've thought about a lot since. A risk manager I respect said: "The market doesn't know your cost basis. It doesn't care what price you paid. It's not going to wait for you."

Paper money — retail, discretionary, people trading their own savings — often acts like the market is paying attention to them specifically. That it will reverse when they've suffered enough, or reward them for conviction.

Institutional money, when it's well-managed, mostly doesn't think this way. Not because institutional traders are smarter people. Because the feedback loops are faster and the consequences of magical thinking are immediate.

That's the discipline. Not intelligence. Speed of consequence.

—C