Can you also explain why a hedge fund portfolio would increase your portfolio’s Sharpe ratio? Already with the returns in the article it’s less than S&P500 so it’s likely somewhere below the CML as the efficient frontier.
That nit picked, the addition of any source of return greater than the risk-free rate, if uncorrelated to the rest of the portfolio, will improve Sharpe. If the return is small, then the optimal allocation is small as well, but still nonzero.
In CML terms, the existence of hedge funds as uncorrelated strategies changes the shape of the CML curve.