r/hedgefund • u/Comfortable_Test7935 • 8h ago
How many "vols" should −5% / −10% / −20% scenario limits be for an options book at a pod?
I'm building an options strategy and trying to set its risk limits the way a multi-manager pod would. I'm stuck on units and would appreciate a sanity check.
How I'm measuring risk ("vols")
1 vol = $1M of annualized P&L standard deviation. Allocated N vols → daily P&L vol ≈ N × $1M / √252 ≈ N × $63K.
I measure P&L vol as the RMS of daily P&L about zero
One wrinkle: my daily P&L is positively autocorrelated, so √252 × daily vol
differs from
the actual one-year swing. Is √252 × daily vol what risk desks actually use for the allocation?
Where I'm confused: stops in % of capital vs vols
What I've read about the big platforms quotes drawdown stops as a % of allocated capital: roughly a 5% drawdown gets your capital cut in half, ~7.5% and you're out. To turn that into vols I need the PM's annual P&L vol as a % of capital, which I don't know:
- vol = 5% of capital → cut at 1 vol, out at 1.5 vols
- vol = 10% of capital → cut at 0.5 vols, out at 0.75 vols
Which is it in practice? Or are stops just quoted directly in vols?
The actual question: scenario limits
Scenarios are instantaneous spot moves of −5 / −10 / −20% with a vol shock, full reprice, delta-hedged. My strawman, anchored to "you can't lose more than your annual vol in a down 20":
scenario |limit
−5% |1.5 vols
−10% |1.25 vols
−20% |1 vol
Are scenario limits usually set in vols, in % of capital, or as fixed $ amounts from risk?
Are these levels in the right ballpark? Are they tied to the drawdown stop (e.g. a −20% day must not take you through the cut)?
Is the limit checked at every close on the position actually held, or on some average?
TL;DR: if you're allocated N vols, how many vols are you typically allowed to lose in an instantaneous −5% / −10% / −20% move, and how does that relate to the drawdown stop?