Weaker Thanks to 2 Kinds of "Supply"

At its core, the bond market is like any other financial market, and securities are like almost any other commodity/good/service when it comes to the laws of supply and demand. That means we can reconcile today's weakness in bonds by talking about factors that may have decreased demand or increased supply. The latter is the easier discussion today. We're in the middle of this week's Treasury auction cycle, and although that supply is well known ahead of time, it can nonetheless tap the breaks on demand from certain buyers who will wait to buy until the auction or afterward. The other supply was not well known ahead of time.  It came in the form of a $15bln this primer).