I am struggling to interpret my mean-variance / efficient frontier / capital market line results. I have no issues calculating the efficient frontier. However, I do increase the risk-free rate from basically zero to higher values. When doing that, the tangential portfolio initially moves further north-east as excpected, but at some point the tangential portfolio drops to the negative part of the efficient frontier.
While I can't get my head around how to interpret this, it might make sense that no tangential point can be found anymore on the positive part of the effcient frontier, hence the max sharpe ratio is the point with "the least negative" Sharpe?
I optimize to find weights that maximize the sharpe [(mu-rf)/std] under restriction that portfolio weights sum to 100% (short-sales allowed). Maybe I am missig a restriction? IS this solution even feasible?
I would really appreciate help on this.
Enjoy the rest of your weekend. Best regards and stay riskay!