NEW YORK (AP) â¿¿ Stocks that moved substantially or traded heavily Tuesday on the New York Stock Exchange and Nasdaq Stock Market: NYSE Chesapeake Energy Corp., up 54 cents at $16.35 Activist investor Carl Icahn bought a 7.6 percent stake in the natural gas producer and pressed it to overhaul its board of directors. Vail Resorts Inc., up $2.39 at $43.88 A Stifel Nicolaus analyst upgraded shares of the ski resort operator to a "Buy" rating citing encouraging season pass sales. Patriot Coal Corp., up 14 cents at $2.60 The mining company said its chief executive officer is leaving as concerns rise that the company could run short of cash. Interline Brands Inc., up $7.14 at $25.08 The maker of products used by locksmiths and contractors agreed to be acquired by two private equity groups for $810.9 million. Peabody Energy Corp., up $1.34 at $25.22 A Goldman Sachs analyst upgraded the mining company citing an expected rebound in coal prices and stronger demand in China. Nasdaq Spreadtrum Communications Inc., up $1.71 at $18.20 A JPMorgan analyst upgraded the Chinese chip maker's shares, saying that its chips will be in several of China Mobile's phones. Sanderson Farms Inc., down $1.65 at $52.66 Shares of the chicken processor fell even as it said it returned to a second-quarter profit as its revenue rose from a year earlier. Lululemon Athletica Inc., up $2.51 at $74.57 A Sterne Agee analyst maintained his "Buy" rating on the athletic and yoga apparel maker citing its innovation and store growth.