Ebola, ISIS, Hong Kong and Ukraine: they all added up to a foul brew of troubles for investors who handed stocks their worst start to October since 2011. The rout, which trimmed more than 200 points off the Dow, was led by some unsettling news about manufacturing and by a drop in airline shares on Ebola worries. The CDC announced late Tuesday the first diagnosis of a patient with the deadly disease outside of Africa. The patient traveled from Liberia to the United States on Sept. 19.

"In the here and now, there are too many global-macro concerns for investors to have confidence," said Art Hogan, chief market strategist at Wunderlich Securities, listing a slew of worries, including "Ebola, which is causing things like airline stocks to go down." Airlines were hard hit as investors feared people would be discouraged from traveling. Adding to worries: The Institute for Supply Management reported its manufacturing index hit 56.6 last month and a separate report had construction spending dipping 0.8 percent in August.

IN-DEPTH

-- NBC News Staff, Reuters and CNBC