The three most important letters in health care reform

Have you ever heard of the MLR? It's the percentage of health insurance premiums that the company actually spends on medical treatment. And it's very important.

"A case in point is Aetna, the nation's third largest publicly-traded health insurance plan. Three years ago, the company reported that its quarterly MLR had inched up from 77.9 percent to 79.4 percent in 12 months. On the day this was disclosed, Aetna's share price plunged 20 percent as investors sold off their shares, reducing the company's market value by billions of dollars."