The yield curve is getting steeper. This is often a sign of faster economic (and stock market) growth. I just got out of a meeting with some of the super-rich one-percenters. They are talking about a stock market "melt-up" and are positioning their portfolios to take advantage of this possibility. 

Data for the graph is free at the U.S. Dept. of the Treasury: http://www.treasury.gov/resource-center/data-chart-center/interest-rates/Pages/TextView.aspx?data=yield