After weeks of anticipation and buzz, social game maker Zynga's initial public offering quickly soured on Friday, with shares dropping into negative territory in the first hour of trading.

The company's stock opened at $11 a share on Nasdaq, up 10% from its initial public offering price of $10, but within the first 10 minutes of trading it "broke," falling below its IPO price. Zynga sold 100 million shares at the high end of its expected range of $8.50 to $10. Shares were changing hands recently at $9.68, down 3%.