US markets suffered further losses overnight, as the third quarter earnings got off to a shaky start on the back of Alcoa's poor outlook.

Although the aluminium giant's quarterly earnings and revenue topped estimates, investors were taken aback by its downbeat outlook for global commodity demand.

Chevron also weighed on the market after warning that falling energy prices would result in substantially lower earnings. The S&P logged its fourth consecutive losing session, shedding 0.6%. The benchmark index is now down more than 2% since Ben Bernanke announced QE3 late last month.

Elsewhere, the Dow slumped 129 points (-1%) to 13345, largely on the back of a slide in Alcoa and Chevron shares. The wild swings in oil continued, this time with crude slumping 1.2% to US$91.25. Analysts are anticipating tomorrow's weekly supply report will reveal another rise in crude inventories.

The greenback fell against a number of other currencies, including the euro. The shared currency posted slight gains amid hopes Spain is nearing a formal request for a sovereign bailout.

Elsewhere, the Aussie was buying US$1.0237 ahead of today's domestic jobs data, slated for release at 11:30am, AEDT. Expectations are that the economy added 5,100 jobs in September, but the unemployment rate rose from 5.1% to 5.3%.

Morning Market Analysis: US Markets Down is a post from: Australian Stock Report Market Pulse Blog