In contemplating the recent financial panic, it is easy to get lost in the weeds of repo markets and asset-backed securities and lose sight of the fact that, at the fundamental level, the panic was about inadequate information. Investors were uncertain about what particular assets were worth, and they were uncertain about which banks were exposed to those assets and to what degree. They were also uncertain about how the government would handle undercapitalized banks. It was against this background that the Treasury announced in February 2009 that the nineteen largest U.S. bank holding companies would be subject to an unprecedented stress test to determine if the banks had sufficient capital to survive and maintain lending in the event of a worse-than-expected recession. In this post, I discuss a recent New York Fed staff report that I wrote with Stavros Peristiani and Vanessa Savino that provides evidence that the stress test supplied new information to the market, and thus may have helped quell the panic.