A lesson in mathematical hubris and the perils of thinking you know statistics because you can do math: berkshireeagle.com/news/local/…

Can anyone give me an example of a sequence of random variables such that their pairwise covariances are all negative?

I mean $Var(X_n, X_m) < 0$ for all $n /neq m$. Not sure how to find such a sequence :/

@Sawarnik That's best asked on our main site. One common example is a sequence of values obtained in any random sample of a finite population without replacement.