U.S. stocks traded higher Monday, as the Dow Jones Industrial Average climbed 66 points to 10517, the Standard & Poor's 500 rose 5 points to 1123 and the Nasdaq Composite moved up 5 points to 2315. Among the companies whose shares are actively trading in the session are Alcoa Inc. (AA) Ralcorp Holdings Inc. (RAH) and California Pizza Kitchen Inc. (CPKI). Material stocks, particularly those most closely tied to the worldwide economy, climbed aggressively as the Chinese government announced plans to allow more flexibility into the exchange rate on its currency, alleviating fears that a tightening there would clamp down on demand. Aluminum giant Alcoa ($11.90, +$0.79, +7.11%) was among the biggest gainers of the day, while its smaller rival Century Aluminum Corp. (CENX, $10.91, +$0.87, +8.67%) also climbed. For miners, Cliffs Natural Resources Inc. (CLF, $59.40, +$3.18, +5.66%) and Freeport-McMoran Copper & Gold Inc. (FCX, $68.67, +$2.77, +4.20%) rose, while steel companies U.S. Steel Corp. (X, $45.72, +$2.31, +5.32%) and AK Steel Holding Corp. (AKS, $14.50, +$0.60, +4.32%) also rose. Meanwhile, coal companies were also getting a boost as Credit Suisse listed them among those to benefit and as data from China showed imports of coal did indeed remain well above year-ago levels in May. Among the gainers were Massey Energy Co. (MEE, $32.64, +$1.34, +4.28%), Peabody Energy Corp. (BTU, $42.47, +$1.21, +2.93%), Patriot Coal Corp. (PCX, $16.52, +$0.62, +3.90%) and Arch Coal Inc. (ACI, $23.31, +$0.66, +2.91%). Ralcorp Holdings ($57.70, -$4.47, -7.19%) agreed to buy American Italian Pasta Co. (AIPC, $52.58, +$10.85, +26.00%) for $1.2 billion and has closed on two small Canadian-based cracker makers. Separately, Ralcorp projected fiscal third-quarter earnings below analysts' average estimate. The downbeat forecast was attributed to cereal trends including lower returns on promotional spending and the impact of branded competition. California Pizza Kitchen ($17.01, -$1.88, -9.95%) lowered its second-quarter expectations as results in recent months came in worse than expected. The company on Monday cut its second-quarter earnings projection to 10 cents to 15 cents a share from May's target of 24 cents to 26 cents, above analysts' then-expectations. BP PLC's (BP, $30.82, -$0.94, -2.96%) U.S. shares fell following a statement late Friday indicating its partner in the leaking Gulf of Mexico oil well, Anadarko Petroleum Corp. (APC, $43.65, +$1.08, +2.54%), plans to refuse paying its share of escalating cleanup costs. Meanwhile, BP said costs for the Gulf spill response reached $2 billion as it continues work to contain the leak and to pay claims for damages. Affymax Inc. (AFFY, $7.30, -$15.71, -68.27%) provided study results for its Hematide treatment of anemia in chronic renal failure patients, saying primary efficacy endpoints were met in each of four Phase-3 studies. But its shares sank as the company said a subgroup of nondialysis patients saw a higher frequency of CSE events, which can include death, stroke, congestive heart failure and other problems, in the group given Hematide than in a comparator. The issues with Affymax's secondary endpoints are viewed as good news for competitor Amgen Inc. (AMGN, $56.66, +$1.46, +2.64%). Hematide aims to be a longer-lasting alternative to Amgen's anemia drugs Aranesp and Epogen. U.S.-based Valeant Pharmaceuticals International (VRX, $46.35, +$0.48, +1.05%) and Canada's Biovail Corp. (BVF, $16.28, +$1.68, +11.51%) Monday said they plan to merge to create a specialty pharmaceuticals group focusing on neurological products, dermatology and generic medicines in Canada and emerging markets. Other Stocks In Focus BioSante Pharmaceuticals Inc. (BPAX, $1.95, -$0.14, -6.70%) said it has gotten commitments from several institutional investors, including Deerfield Management Co., to buy $15 million of stock and warrants. CNB Financial Corp. (CCNE, $11.44, -$0.31, -2.64%) said it would sell 3.37 million shares at $10.25 each, a 13% discount to Friday's closing price. The bank holding company said it would use proceeds for general purposes, including expanding its business and investments in its subsidiary. Hilliard Lyons raised its stock-investment rating on medical-technology company Computer Programs and Systems (CPSI, $37.81, +$1.50, +4.13%) to long-term buy from neutral, saying the stock has fallen 15% over the past week, and analyst Tom Carpenter feels this is a buying opportunity. (MORE TO FOLLOW) Dow Jones Newswires June 21, 2010 13:27 ET (17:27 GMT)