First Marblehead ( FMD) plunged 11.6% to $3.45. The stock moved up on Thursday based on positive comments by an analyst and the selling is thought to be profit-taking as the stock recently has had very few upward trading days. Shares of US Airways ( LCC) sank to a new 52-week low on a spate of bad news. The Tempe, Ariz.-based airline said that thanks to rising fuel costs it would delay opening a route from Philadelphia to Beijing and raise its fares as much as $60 roundtrip. S&P put nine airlines, including US Airways, on negative CreditWatch. Credit Suisse downgraded the stock to underperform from outperform, and UBS cut its price target for US Airways and six other airline stocks. The stock shed 18.6% to $4.25 Friday. Elsewhere, insurance companies fell across the board after Moody's downgraded American Insurance Group's ( AIG) debt rating with a negative outlook. The downgrade was based on the losses the insurance giant has suffered as a result of the mortgage market meltdown and credit market disruptions. AIG fell 2.3% to $36.96. Fellow insurance companies tumbled as well with MBIA ( MBI) dropping 7.9% to $7.41 and Ambac ( ABK) declining 5% to $3.22. Shares of CA ( CA) were up 93 cents, or 3.9%, to $25.10 after the company guided current fiscal year revenue and earnings above Street expectations. However, fourth-quarter EPS came in below analysts' estimates. CA posted an 18% increase in revenue to $1.09 billion for the quarter. Net income was $71 million and EPS, excluding items, was 22 cents. Analysts were expecting revenue of $1.09 billion and EPS of 28 cents.