We are well into our first heat wave of the season, and it has been brutally hot. The heat index has been a very important number to pay attention to, and that will continue as we head into the ...

See the historical performance of the S&P 500 Index. Learn more about the factors that affect the S&P 500 average return.

The Nasdaq is the second-largest stock exchange in the world, listing over 3,000 securities, including most tech companies. Learn how to use the Nasdaq to invest.

The latest stories from our Planet or Plastic? series—a multiyear effort to raise awareness about the global plastic waste crisis.