DURING BOUTS OF FINANCIAL TURBULENCE, EMERGING markets have typically been the first to suffer. Sharp currency moves, interest rate spikes or liquidity crises usually spark a flight to quality, benefiting the dollar and U.S. Treasuries and slamming equity and bond prices in developing countries. But as the blowup of the U.S. subprime mortgage market spread panic through capital markets recently, a curious thing happened: Investors for the most part kept their nerve -- and their positions in emerging markets. Welcome to the new world of global investing. Ten years after the Asian currency crisis triggered deep recessions across the region and turmoil throughout world markets, emerging markets are serving as a source of stability rather than contagion. Sound policies and strong economic fundamentals have left these countries better placed than ever to ride out the subprime-spawned credit storm. Just so, emerging-markets securities have gone from being a niche opportunity for...