Years ago, the infinite decimal 3.14 or its Greek symbol pi was mostly known to math and science geeks, but now March 14 is also a day for tasty deals. Here’s a little history to whet the appetite.

2-Year U.S. Treasury Note Continuous Contract $103.617 0.152 0.15% 5-Year U.S. Treasury Note Continuous Contract $108.102 0.445 0.41% 10-Year U.S. Treasury Note Continuous Contract $111.250 0.672 ...