When a Stock Market Theory Is Contagious

"Jesse Livermore," who pseudonymously blogs at Philosophical Economics, predicted on the eve of the Alibaba IPO that the market would put in its yearly high in the first hour of trading on that day. He nailed that trade to the 

This week's sell-off on both sides of the Atlantic has unnerved investors. Here are some reasons why markets are so fearful.

"Jesse Livermore," who pseudonymously blogs at Philosophical Economics, predicted on the eve of the Alibaba IPO that the market would put in its yearly high in the first hour of trading on that day. He nailed that trade to the 

The stock market has already had a crazy day on Wednesday. Minutes after the market open, the Dow fell as much as 385 points while the S&P 500 and Nasdaq were both down more than 2%. But the craziest move came in 

In the stock market, a placid spring and summer have given way to a stormy fall. After going nearly all of May, June and July without so much as a 1 percent one-day change, the Standard & Poor's 500 has made such fluctuations a regular habit in October.