The reason YC gave for the rejection was that Mexico was an unknown market, and they felt lending in there was too risky for them.
Makes me wonder what was the decision logic to accept this Stablegains, against that background it doesn't make any sense.
Was YC aware of the ponzi nature of this thing and decided to dip in? It just makes no sense.
It's extremely profitable to invest in a Ponzi if you are early to the scheme.