Stocks that moved substantially or traded heavily Tuesday on the New York Stock Exchange and Nasdaq Stock Market:
US Airways Group Inc., up 44 cents at $11.62
The airline said that a key measure of passenger revenue rose about 6 percent in May compared with the same month last year.
Dollar General Corp., down $1.73 at $46.76
The discount retailer said that its first-quarter profit rose 36 percent, but its revenue was just below Wall Street expectations.
Mednax Inc., up $1.44 at $61.64
A Stifel Nicolaus analyst initiated coverage of the medical group with a "Buy" rating, citing the company's prospects for growth.
Starbucks Corp., down $1.49 at $52.41
The coffee chain said that it is increasing its offerings in the highly competitive food market by buying a small bakery chain for $100 million.
Complete Genomics Inc., up 14 cents at $2.18
The life sciences company will lay off about 20 percent of its workforce to cut costs and explore "strategic options."
Westport Innovations Inc., up $4.75 at $27.02
The natural gas engine maker said that it reached a deal with Caterpillar Inc. to jointly develop engines for off-road equipment.
G-III Apparel Group Ltd., up 93 cents at $24.93
The apparel maker said that its first-quarter loss widened, but its results met the expectations of Wall Street analysts.
Layne Christensen Co., up 62 cents at $19.22
The drilling and construction services provider said first-quarter net income fell, but its revenue rose and beat analysts' expectations.