1. BOJ hints at possible interest-rate increase, surprising investors. 2. Japan's 10-year bond yield hits 1.879%, highest since June 2008. 3. U.S. 10-year Treasury yield rises to 4.095%, affecting borrowing costs. 4. Concern grows that rising Japanese yields may divert cash from U.S. investments. 5. S&P 500 fell 0.5% amid fears of climbing Treasury yields.