Return jumps on equities exhibit slowly-decaying tail behavior admitting severe downside risk; moreover, heavy-tailed jump size distributions governing these rare events pose further challenges to econometric estimation. This paper formulates a portfolio choice problem in a multi-asset...

We study effects of correlation ambiguity on portfolio choice when the number of risky assets is large. We find that the optimal portfolio contains only a fraction of available risky assets. With 100 stocks randomly selected from the S&P 500, less than 20 stocks will be held in the optimal...