I cannot seem to figure out the correct way to go about creating a custom factor that takes the price of the assets and divides them by the price of the SPY.
Some built-in factors such as linear_regression() seem to be able to take an argument specifying a separate target symbol and do a regression analysis on all symbols vs. that target. This is basically what I am trying to do, but instead of performing a regression, I just want to do a simple division operation.
Is this possible?