The best single measure of where valuations stand at any given moment is the ratio of the total market capitalization to the total dollar value of the GDP. And any time that valuation stands at more than 100% of the total goods and services in the economy means it is time to be wary about common stocks.

Amazon.com (Ticker Symbol: AMZN) is an American multinational electronic commerce company with headquarters in Seattle, Washington, United States. It is the world’s largest online retailer. The company also produces consumer electronics — notably the Amazon Kindle e-book reader and the Kindle Fire tablet computer and is a major provider of cloud computing services.

In January 1994, Jerry Yang and David Filo were graduate students at Stanford University when they created a website named “Jerry’s guide to the world wide web”. David and Jerry’s Guide to the World Wide Web was a directory of other websites, organized in a hierarchy, as opposed to a searchable index of pages. In April 1994, “David and Jerry’s Guide to the World Wide Web” was renamed “Yahoo!” — the “yahoo.com” domain was created on January 18, 1995.

Shares of online radio firm Pandora Media Inc. plummeted on their second day of trading as the Pandora IPO date departed and investors suddenly fled for the exits. BTIG analyst Richard Greenfield this afternoon launched coverage of Pandora Media with a Sell rating and a $5.50 price target.

If your stock makes a big move while you’re stuck in traffic, don’t worry — TD Ameritrade (Stock Symbol: AMTD) lets you buy and sell even when you’re on the go.