How to calculate?


I would like to ask if anybody know how to calculate break even point of number of loans in peer to peer lending?
How much (number of loans) you should have, to diversified your portfolio.
I know you should spread your investment on a marketplace over at least 100 different loans, better 200 or 400 different loan parts.

See chart on the lower left of the following page for stats based on Lending Club data (Diversification Can Reduce Volatility of Returns)

How can I calculate this in STATA or EXCEL?

Any suggestion, article or resarch paper on this topis is welcome :)

Kind regards