S&P 500 Index: What It’s for and Why It’s Important in Investing

The S&P 500 (Standard & Poor's 500 Index) is a market-cap weighted index of 500 major U.S. companies—an essential benchmark ...
The Motley Fool

What Is Herfindahl-Hirschman Index?

HHI helps assess market competitiveness by calculating company market shares. A HHI below 1500 indicates a competitive market, above 2500 suggests concentration. Use HHI to guide investment decisions, ...
WRAL

Ask the Meteorologist: Why do we use the heat index so often in the summer months?

"It's not the heat. It's the humidity." Sound familiar? I think we're all guilty of saying that at some point between June and September. The heat index isn't just some made-up number to inflate ...