Hi quant experts,
I'm frustrated to the point of considering giving up on Quantopian.
I'm having trouble creating a CustomFactor using historical fundamental factors.
I'm trying to do something simple as calculating the average 5-year gross margin or 1-year ago TTM ROA.
I searched the forums but all I could find is questionable hacks.
It would be awesome if anyone can guide me on the matter.
Thank you so much,