That mistake, plus Block's lower-than-expected earnings for the quarter, caused its stock price to drop by 8.5 percent in one day.

The company, which provides crop insurance, reported lower-than-expected earnings.

Novell, a computer networking software company, also reported lower-than-expected earnings yesterday.

On Wednesday, the stock plummetted 4 3/8, after the company reported lower-than-expected earnings for its second-fiscal quarter.

The carrier also reported lower-than-expected earnings for the third quarter.

All of the price drop occurred before it announced, after a halt in trading, that it would report lower-than-expected earnings.

The company attributed the lower-than-expected earnings in part to growing demand for its lower profit-margin products, like personal computers and computer work stations.

The first of several warnings about lower-than-expected earnings came shortly after.

They cited Ford's lower-than-expected fourth-quarter earnings as evidence that steadily growing competition will cut into profit margins in coming years.

Intel fell 15/16 a share, to 85 3/8, after tumbling more than five points Wednesday when it posted lower-than-expected earnings.