UPDATE: It appears the site is up for some (premium members?)
When we first noticed, we assumed Treasury.gov was down for un-scheduled maintenance, but now, 10 hours later, it appears the site is down for other reasons? Overwhelmed by NSA DDoS attacks (as government pension funds seek more information on where their investments are heading)? Sequestration claimed the Webmaster? Hacked? Or simply the first cost-cutting measure for a Fed who just suffered their largest loss ever in a quarter (of course, that is, if they were bound by 'normal' mark-to-market rules). There are no explanations as yet.