NEW YORK (TheStreet) -- The Shanghai Composite fell 8.5% on Monday, dragging the S&P 500 lower by 0.6%. The U.S. index is now down almost 3% over the past week and has investors thinking about a possible larger-scale correction. It hasn't been pretty as the S&P 500 has declined for five straight days, Guy Adami, managing director of stockmonster.com, said on CNBC's "Fast Money" TV show.