All the major stock indices have now plunged nearly 15 percent since the last week in July.

The Dow was off 14.32 percent as of 1:30 p.m. CDT on Monday. The S&P was down 16.08 percent; the Nasdaq 15.98 percent.

Investors are sellilng stocks with both hands. What are they buying? Treasuries, or debt offered by the no-longer triple-A rated U.S. government.