The euro has weathered the worst financial crisis since the Great Depression, bailouts of Greece, Ireland and Portugal, and falling interest rates. Now, investors are betting like never before that a Greek exit would be too much to keep the 17-nation currency above its long-term average. Hedge funds and other large speculators, which pared trades that would profit from a drop in the euro to the lowest levels since November, rebuilt them to a record high last week, figures released May 18 by the Washington-based Commodity Futures Trading Commission showed.