Using ITS design approaches, I analyze the public finance market in the context of a 2012 SCOTUS decision. I find that the court decision had significant effects on investor behavior in the hospital sector of the public finance market as manifested in trade volume and price changes. These effects appear to contradict models of market efficiency and are more consistent with behavioral financial economic theory. These volume and price effects are quite heterogeneous across states in patterns that comport with assumed investor expectations with respect to a quasi-experiment that emerged as a result of the SCOTUS decision. Differences in investor expectations concerning bond risk, among other factors, may explain these effects.