Easy come, easy go. As investors mark the anniversary of

Nasdaq 5000 with pits in their stomachs and holes in their pockets, a profit warning from


(INTC) - Get Report

has brought the major stock market indices to their knees.

Yesterday evening, Intel announced that first-quarter revenue would fall about 25% below fourth-quarter levels. The semiconductor manufacturer also said that it would eliminate 5,000 jobs. In recent trading, the chipmaker was trading down 9.4% to $30.17. The

Philadelphia Stock Exchange Semiconductor Index

, which tracks the chip industry, was lower 4.3%.

In its statement, the chipmaker cited familiar culprits for its shortfall: slowdowns in PC demand and the broader U.S. economy. Intel chairman Andy Grove had given Wall Street a heads-up prior to last night's announcement, confessing on Tuesday night that he didn't see demand for semiconductors snapping back quickly. Among the investment firms to cut their earnings-per-share estimates for Intel this morning were

Lehman Brothers


Credit Suisse First Boston


Merrill Lynch


Prudential Securities


To be sure, Intel was not the only technology bellwether in hot water this morning. Citing a source close to


(CSCO) - Get Report



reported this morning that the networking equipment manufacturer planned to cut 5% of its workforce. At last look, Cisco had shed 5.2%.

Elsewhere, speculation that


(MSFT) - Get Report

will follow Intel with a warning, dragged its stock down 2.1% to $58 in recent action. Back in January, Microsoft memorably issued a profit warning for the first time in a decade, pointing to a falloff in demand for computers.

Making matters worse this morning was a stronger-than-expected

employment report.. New nonfarm payrolls for the month totaled 135,000,

almost double the 68,000 economists were forecasting. Unemployment stayed put at 4.2% -- economists had expected it to tick up to 4.3%.