The big story in markets this past week was not on the equity side of things but in the interest rate realm.
The yield on 30-year and 10-year US Treasuries hit new multi-year highs, continuing this year's theme of higher rates.
Nomura's George Goncalves says the bond weakness has to do with angst surrounding the next Fed chair, and the possibility that Larry Summers will be appointed, and take the Fed in a more hawkish direction, meaning fewer asset purchases, and a faster move away from zero interest rates. NOMURA: Bonds Fall On Concerns That Larry Summers Will Be Hawkish - Business Insider
Might as well throw his opinion, off-the-wall as it may be, into the realm of speculation.