I’ve significantly improved on my Markowitz algorithm.
It’s a merge of two tutorials (but I’ve read 3). Currently I derive weights based on the optimal sharpe ratio. ATM I don’t take into consideration any interest free rate (i.e. its simply return/volatility).
I was trying two different solver methods. Minimize was taking a really long time, so I tried this other tutorial that made use of cvxopt and a quadratic equation (which I use to draw the efficient frontier rapidly). I was unable to find the optimal value based on sharpe ratio using the cvxopt solver… (it would only solve either the bottom or topmost portion of the line) so I looked at finquant and it uses a montecarlo of 5000 to derive the optimal points (i.e. max return, min volatility, and max sharpe ratio).
So I fell back on monte carlo to do it for me. i.e. “The path of least resistance” and the margin of error is acceptable.
The import thing is it’s very fast/ straightfoward (KISS). So I will use this to backtest with.
What I like about Markowitz is it assumes past behavior is a good model for future (t tests in stocks are used to determine if two partitions of returns are equal). It’s been said that yesterdays price is the best predictor for tomorrows. Same for returns.