PIMCO bond guru Bill Gross thinks the U.S. economy will grow at a 1.5% pace over the next decade, far below its historical norm. 

“Slower growth means lower returns on capital,” Gross tells Bloomberg News. “If real GDP grows at 1.5 percent, then a diversified portfolio of stocks and bonds would probably grow at 1.5 percent, as well.” He cited several factors in his reasoning for the slower growth prediction, including slower labor force expansion, overextended credit, and possible geopolitical or environmental shocks.

Bloomberg reports that Gross kept the portion of his Total Return Fund invested in Treasurys steady at 35% in June, the highest since February. He has recently said that U.S. securities are the safest bet for investors.