One (1) Standard Deviation as "Volatility" in Portfolio Management (Framing)

CFA Level III Portfolio Management
#1

I haven’t formally worked in PM space so just curious…The CFA curriculum uses One (1) Standard Deviation and “Volatility” interchangeably, as the most prominent metric of how “risky” an asset or asset class can be. Does the PM industry do this as well in presentations to prospective investors?

Feels to me that presenting just One (1) Standard Deviation is pretty misleading in that 32% of returns (assuming ND) will actually lie outside that range. Sort of like the elephant in the room of Framing Biases.

There’s no perfect way to present it but would 2 Std Dev (95% confidence) be at least more appropriate?

#2

Not an industry perspective, but I’m not sure 1SD is misleading as long as it’s clear what you’re showing.

If the sample size, mean, and SD are clearly identified so the audience can do what they want with it, then that’s fair. However, a plainly stated interval of (lower, upper) without any description (i.e. this is mean +/- 1SD representing 68%…) would be inappropriate and misleading because the audience has no idea if it is 1, 1.5, 3 SD… so on and so forth.

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