A messy breakup between Harley Bassman, the derivatives expert who invented the main gauge of Treasury volatility, and his former employer has escalated after the bond veteran sent a letter to the firm’s shareholders challenging its business practices.
Source: [Bloomberg Markets](https://www.bloomberg.com/news/articles/2026-09-14/bond-veteran-bassman-escalates-clash-with-14-billion-etf-issuer)