Small chipmaker Micrel Semiconductor ( MCRL) sunk 19.7% after it reduced its fourth- quarter guidance. The company said it now projects revenue to be approximately $64 million, which is lower than its Oct. 25 forecast of $66.5 million to $67.8 million.

The shortfall is attributed to lower-than-expected orders from customers in China and Korea. Earnings are now forecast in the range of 10 cents to 11 cents, compared with previous guidance of 13 cents. Shares of Micrel were off $1.54 to $6.28.

Apple ( AAPL - Get Report) has retreated significantly from the $200-mark on Dec. 26 and was off $14.88, or 7.6%, to $180.05 Friday.

The stock was down despite a research note from Goldman Sachs that said Apple enjoyed good holiday sales and is likely to report strong earnings in the first quarter. Goldman also raised its six-month price target for Apple stock to $220 from $205.

Regions Financial ( RF - Get Report) plunged 10.7% to $20.80, after the Alabama bank said it will set aside some $360 million in the fourth quarter to cover bad credit, compared with $270 million last quarter. The provision, the girth of which is largely due to Regions' souring portfolio of homebuilding loans, comes to 1.45% of total loans vs. 1.19% last quarter.

Among the few financial winners on Friday was Michigan insurer North Pointe ( NPTE), shares of which rocketed 45.9% after Australia-based QBE Insurance agreed to buy it for $16 a share in cash, or about $146 million. The deal should close in the first half. North Pointe shares soared $4.86 to $15.44.

Shares of Cleveland BioLabs ( CBLA) tanked $4.80, or 60%, to 3.20 after the company said Friday that it wasn't selected for a U.S. Department of Defense (DoD) contract to develop and stockpile a treatment for radiation exposure.

The company said it is very surprised by the DoD's decision and has requested a debriefing to better understand the decision.

On the other hand, having won the contract, Osiris Therapeutics ( OSIR) added $1.15, or 9.2%, to $13.72. Thursday after the market closed, the company said the U.S. Department of Defense will pay it up to $224.7 million to develop and stockpile Prochymal, an adult stem cell treatment for radiation exposure. The stock is a component of the Nasdaq biotechnology index, but it wasn't enough to push it into the green -- the index was down 7.24, or 0.87%, at 827.66.

Thief River Falls, Minn.-based Arctic Cat ( ACAT) fell through the ice after the snowmobile and all-terrain vehicle maker forecast lowered third-quarter 2008 earnings. Citing lower-than-expected ATV sales, Arctic Cat now expects a loss of 55 cents to 60 cents a share, wider that previous guidance of a loss of 30 cents to 37 cents a share. Analysts polled by Thomson Financial expect an EPS loss of 32 cents. Shares slipped 23% to $9.35.

Talbots ( TLB) also slumped, 13% to $9.32, after the Hingham, Mass.-based apparel retailer announced it would close 78 of its stores.

This article was written by a staff member of TheStreet.com.