Today's selling pressure was the strongest since the Monday after the U.S. lost its AAA credit rating in August 2011. Down volume outnumbered up volume on the NYSE by over 70 to 1 (~98%+ down). Stat table below shows days w/ at least 40 down-to-up volume ratio since 1990 w/ $SPX https://t.co/tBljxiL5C0