50 Most Powerful Women

2007 rank: 27
Age: 55

Amid a financial meltdown, J.P. Morgan Chase orchestrated a buyout of Bear Stearns and has seen its stock fall just 1% over the past year. Miller's $7 billion division, which provides cash-management and custodial services, isn't linked to the credit cycle. So the bank relies on this big, stable business during difficult times. Miller delivered 2007 net profits of $1.4 billion, up 62% from 2005.

NEXT: Judy McGrath