Keybanc Capital MarketsOne of the largest high-yield municipal bond borrowings this year, a $610 million deal for a series of New Jersey behavioral health centers, failed to clear the market Tuesday despite offering yields as high as 8.25%. Many investors are unfamiliar with the behavioral health sector, which is poised to grow, O'Grady said. Behavioral health is still in the early stages of development as a defined municipal asset class," he said. Behavioral health has a large potential pipeline of deals that KeyBanc is working to develop, Plank said. "Our work in behavioral health is part of a deliberate, years-long strategy and not a one-off transaction or opportunistic deal," Plank said.