Calculating portfolio drift

Portfolio drift is the gradual change in the allocation of assets in a portfolio over time. This can occur due to a number of factors, including changes in the market value of the assets.

Portfolio drift can have a number of negative effects on the portfolio, such as increased volatility, reduced diversification, and reduced returns. It can also cause the portfolio to deviate from its target allocation, which can affect an investor’s ability to achieve their investment goals.

Let’s look at how we can calculate portfolio drift:

1. First, we need to gather the current situation. We’ll need to have the original model portfolio allocations, how many units we hold of each ETF, and the latest market prices for those ETFs:

   allocations = [obj.percentage for obj in myPortfolio.allocations]

   holdings = [obj.units for obj in myPortfolio.allocations]

   market_values = []

   for allocation in myPortfolio.allocations:

     price = float(yf...