Check out which companies are making headlines before the bell:
Hasbro—Piper Jaffray upgraded the toymaker's stock to "overweight" from "neutral," both on a valuation basis following a recent pullback and benefits from the upcoming introduction of new "Star Wars"-themed toys.
BB&T—The bank's stock was upgraded to "outperform" from "neutral" at R.W. Baird, which called a recent sell-off in the stock a "solid buying opportunity." A similar thesis was put forth by KBW as it upgraded regional bank PNC to "market perform" from "underperform."
General Mills—Morgan Stanley upgraded the food company's shares to "equal weight" from "underweight," citing a more aggressive managing of costs.
AT&T—AT&T was upgraded to "buy" from "neutral" at Citigroup, which said a recent pullback provides an attractive entry point. Citi also cites potential upside from the company's recent acquisition of DirecTV.
Navistar—The truck and engine maker reported its 12th quarterly loss in a row, as its results suffered from restructuring and warranty costs.
Ambarella—Ambarella reported adjusted quarterly profit of 88 cents per share, beating estimates of 80 cents, while revenue was also above forecasts. However, the maker of video processing chips is seeing its shares under pressure, following a report warning of possible risks to GoPro's third quarter results. Ambarella is one of GoPro's key suppliers.
H&R Block—The tax preparation firm posted a loss of 35 cents per share, 5 cents less than analysts had anticipated. Revenue beat estimates, and the company also announced a $3.5 billion stock buyback program.
CBS—The company said its CBS Sports unit would allow expanded streaming of NFL games on portable devices.
Amgen—The biotech firm announced its experimental bone density drug was more effective than an Eli Lilly treatment that is already on the market. The results come from a late-stage study of a drug designed to treat osteoporosis.
Sears Holdings—The retailer's Kmart division paid $1.4 million to settle a U.S. case charging it with inducing Medicare beneficiaries to fill prescriptions at Kmart pharmacies.
Philip Morris International—The tobacco producer is talking to potential investors in its Indonesia cigarette unit, according to Dow Jones. It hopes to start taking orders for shares in that unit on September 21, in a sale that would raise more than $1.5 billion.