Optimism that central banks will stabilize the financial markets boosted the markets to a sharply higher close with the Dow soaring 115 points to 12,767. Nasdaq surged 36 points to 2872.

On the upside

Bargain hunters lifted shares of Zynga (Nasdaq: ZNGA) whose stock price tumbled this week after Cowan and Co. reported an 8% drop in daily active users of Zynga's games on Facebook (Nasdaq: FB).

Shares of e-Commerce China Dangdang (NYSE: DANG) continued rising announcing on Wednesday a partnership to operate the online sales channels for Tencent Holdings.

GOL Linhas (NYSE: GOL) will discontinue its high cost, low profit flights to Santiago, Chile.

On the downside

Alaska Communications (Nasdaq: ALSK) declared a quarterly dividend of $0.05 per share payable on July 18, 2012 to shareholders of record June 29, 2012.

A Seeking Alpha contributor listed Telecom Argentina (NYSE: TEO) as one of three undervalued mid-cap stocks with high yield but the stock price dropped.

Verizon Wireless (NYSE: VZ) named Russ Preite to the position of president of Northern California/Nevada/Hawaii Region.

In the broad market, advancing issues outpaced decliners by a margin of nearly 5 to 2 on both the NYSE and on Nasdaq. The Russell 2000 which tracks small cap stocks climbed 8 points to 771.