No sooner had Martina Hund-Mejean signed on at MasterCard Worldwide than cracks began appearing in the global economy. Within months of joining the $5.1 billion card company as its CFO in November 2007, Hund-Mejean says, she had a sense "that things were not doing so well."

Although Bear Stearns had yet to stumble, "by January 2008, we were already talking with our business leaders, [saying] something doesn't really smell right," she says. "We started to line up contingency plans in case things didn't go the way that we might have forecasted before."

MasterCard makes its money from fees charged on each credit or debit card transaction, and that revenue stream suffered as economic activity slowed. MasterCard had the advantage of going into the financial crisis with "a really sound capital structure," she notes. "We have virtually no debt and we have a significant amount of cash on our balance sheet." (Nor did the company have any exposure to consumers' credit card debt.)