Among the companies whose shares are moving in pre-market trading Wednesday are Alpha Natural Resources, Arch Coal, Zynga, Arena Pharmaceuticals, Alexza Pharmaceuticals, 3D Systems Corp, Green Mountain Coffee Roasters, Autoliv, Seadrill and Kraft Foods.

Alpha Natural Resources, Inc (ANR) shares advanced 1.33 percent to $8.38 in pre-market trading. The company stock declined to a new record low Tuesday after announcing a plan to limit coal mining operations in its northern and southern Kentucky business units.

Arch Coal Inc. (ACI) stock advanced 1.88 percent to $5.97 in pre-market trading. Jenny Herner, ACI vice president of marketing administration, has been named one of St. Louis's 2012 Most Influential Business Women by the St. Louis Business Journal.

Zynga Inc. (ZNGA) stock gained 1.81 percent to $5.07 percent in pre-market trading. The company stock slumped Tuesday on worries that the craze for games on Facebook may have passed its peak.

Arena Pharmaceuticals, Inc. (ARNA) stock advanced 1.52 percent to $8.00 in pre-market trading. The stock has a 52-week low of $1.23, a 52-week high of $7.92 and $1.44 billion in market capitalization.

Alexza Pharmaceuticals, Inc. (ALXA) stock plunged 38.02 percent to $2.25 in pre-market trading. On Tuesday, the company announced 10-for-1 reverse split of its common stock and it became effective Tuesday at 5:01 p.m. EST. At the effective time of the reverse stock split, every ten shares of Alexza's issued and outstanding common stock converted automatically into one issued and outstanding share of common stock without any change in the par value per share.

3D Systems Corp. (DDD) stock plunged 5.36 percent to $30.20 in pre-market trading. The company announced Tuesday that it was offering to sell shares of its common stock in an underwritten public offering of approximately $100 million.

Green Mountain Coffee Roasters Inc. (GMCR) stock plunged 4.33 percent to $20.35 in pre-market trading. Safeway Inc launched under its own store brand five types of filtered coffee pods compatible with Keurig brewers but cheaper than those sold by ailing Green Mountain, whose dominance in that market is being threatened, Reuters has reported.

Autoliv Inc. (ALV) stock declined 2.72 percent to $52.96 in pre-market trading. The stock has a 52-week low of $44.38, a 52-week high of $80.05 and $4.87 billion in market capitalization.

Seadrill Ltd. (SDRL) stock fell 2.65 percent to $32.37 in pre-market trading.

Kraft Foods Inc. (KFT) stock declined 1.17 percent to $37.94 in pre-market trading. The stock has a 52-week low of $31.88, a 52-week high of $39.99 and $68.07 billion in market capitalization.