i don't mind getting different returns, what I am asking about is how the quantopian risk metrics are not documented and don't seem to follow industry conventions.
for example, beta, is a measurment of risk related to some industry "standard index". a value of 1.0 would imply "as risky". a value less than that implies "less risky". so I would assume that an investment into SPY would provide a Beta value similar to that of SPY (which is 1.0) but instead quantopian provides a beta of 0.75,
for alpha, a value of 0.0 means the same return as the standard index, with a value of less than zero meaning the returns are lower than the standard index. So I'm wondering why the Alpha for my example is greater than zero? that implies my returns are greater than the standard index.
thanks for posting the source code links, though skimming it doesn't really help me understand the difference between quantopians values and that of other finance websites.