Among the stock activity stories for Friday, June 5, from AP Financial News: PITTSBURGH (AP) ¿ Shares of AK Steel Holding Corp. jumped Friday, a day after the steel maker announced a $70 per ton customer surcharge for electrical steel products shipped next month. NEW YORK (AP) ¿ Harley Davidson Inc. shares slid Friday after a Citi Investment Research analyst downgraded the stock, citing concerns about sluggish U.S. retail sales and a slump in international markets. NEW YORK (AP) ¿ Sales will be pressured and costs will rise for Chipotle Mexican Grill Inc., an analyst said Friday, downgrading the stock. NEW YORK (AP) ¿ Kenexa Corp. shares jumped Friday after the Labor Department reported another 345,000 jobs were lost in May, not as many as analysts anticipated. WASHINGTON (AP) ¿ Shares of Cascade Corp. sank Friday after two Wall Street analysts downgraded the company following a disappointing fiscal first-quarter report. NEW YORK (AP) ¿ Shares of Berry Petroleum Co. jumped Friday after an analyst upgraded the independent oil and gas producer, saying it will likely benefit from rising oil prices.