Not in any particular order...just 10 to consider. 01. short sellers 02. margin call sellouts 03. 401k/mutual fund investors pulling funds, forcing funds to sell into a down market 04. downgrades (which often come out after a stock tanks by slow analysts) 05. layoffs/fear of jobloss = less capital = less investors 06. tightening of loans = less capital = less investors 07. news perpetuating fear/pushing away retail buyers/especially with all the foreign market declines being shown as well 08. the irratic behavior of the fed/govt doing things that don't help and maybe make things worst with market manipulation practices. People don't want to invest in things that are artificially propped up. Especially big money that knows better. 09. Take all the above and apply it to foreign countries, companies, investors in the U.S. market who are more reactionary. 10. Major rightdowns coming out after numbers have to be recalculated.