Garment workers and relatives of Rana Plaza victims stage a demonstration on the outskirts of Dhaka, Bangladesh, Dec. 24. Shariful Islam/Xinhua/Landov hide caption

itoggle caption Shariful Islam/Xinhua/Landov

Round-tripping occurs when American citizens open bank accounts in tax havens such as the Cayman Islands, funnel money into the accounts and then use it to buy stocks and bonds back in the U.S. David McFadden/AP hide caption

itoggle caption David McFadden/AP

"The stock market is rigged," says Michael Lewis, and high-frequency traders are to blame. But defenders of high-speed trading say it plays a legitimate role. Paul Giamou/iStockphoto hide caption

itoggle caption Paul Giamou/iStockphoto

Russian President Vladimir Putin looks on as Crimean leaders sign a treaty for Crimea to join Russia on Tuesday. In response, Western countries have imposed limited sanctions. Sergei Ilnitsky/AP hide caption

itoggle caption Sergei Ilnitsky/AP