Stocks that moved substantially or traded heavily Tuesday on the New York Stock Exchange and Nasdaq Stock Market:
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.
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.