Tagged Questions
9
votes
1answer
383 views
How are Expected Shortfall and Variance related?
I would like to know how Expected Shortfall $SF_\alpha$ and variance $\sigma^2$ are related.
If I follow what Aaron Brown answered in this post, when the underlying distribution is Normal with ...
13
votes
3answers
3k views
What is the best way to “fix” a covariance matrix that is not positive semi-definite?
I have a sample covariance matrix of S&P 500 security returns where the smallest k-th eigenvalues are negative and quite small (reflecting noise and some high correlations in the matrix).
I am ...
6
votes
2answers
191 views
Is it better to grade hedging strategies based on the sum of absolute or squared hedging errors?
Let's say I have one strategy that has a hedging error of:
2,
2,
-2,
-2
Let's say I have another strategy that has a hedging error of
.5,
.5,
3,
3
Would it be a better idea to grade the hedging ...
5
votes
1answer
2k views
Annualzing the log of daily returns riddle
Two popular ways to measure returns are Arithmetic returns and Log returns. Let's define arithmetic (simple period) returns as: P(t) - P(t-1) / P(t-1). Let's define log return as Ln( P(t)/P(t-1) ) or ...
