Martin Baccardax Japanese bond yields are spiking—and that could mean big trouble for U.S. stocks. Japan's benchmark 10-year government-bond yields briefly topped 2.9% on Thursday, a level that still sits well below the current 4.57% yield on U.S. Treasuries but nonetheless represents the highest in three decades. The recent selloff in JGBs, in fact, is now in its ninth consecutive session, the longest in nearly 20 years.