Diego Megia raised $1.5 billion this spring and bet interest rates would go down. It backfired.

The firm's TSO fund — which runs a concentrated strategy that made a large bet on European interest rates going down — is down 12.8% through September since it launched six months ago, two people familiar with the matter told Business Insider. The strategy lost 12.2% in September alone, the two people said, meaning a vast majority of the fund's losses came last month.

The firm raised $1.5 billion for the young fund in March, and backers can't redeem their capital until next spring, the people added.

Taula declined to comment.

Global interest rates have jumped thanks to sticky inflation, the…