For stock market, it's welcome back to 2011 – CNBC.com

Parts of Europe are in deflation, growth worries continue in China, and Islamic extremists have added a new layer of instability to the Middle East.Read MoreOptions trader bets big time on bottom for stocksPerhaps predictably, stocks have wobbled, with a series of triple-digit up and down moves on the Dow industrials and another round of worry that the long-anticipated correction […]