Theravance Inc. (NASDAQ:THRX) is down 31.73% in early trading at $13.82. THRX is down on heavy volume with 354 thousand shares traded, more than 5 times its daily average volume. THRX shares are down after their drug failed in trials. The company has a market cap of 1.18 billion.

Perfect World Co., Ltd. (NASDAQ:PWRD) is down 23.33% today at $9.20. PWRD has traded 2.7 million shares so far today, well above its daily average of 639 thousand shares. The company has a market cap of 417.17 million.

Health Management Associates Inc. (NYSE:HMA) is down 9.61% today at $6.77. HMA has traded 3.9 million shares today, 400 thousand more than it trades a day on average. The company has a market cap of 1.68 billion. Sign Up For Our Free Weekly Newsletter

TransAtlantic Petroleum Ltd. (AMEX:TAT) is down 10.56% today at $1.27. TAT has traded 646 thousand shares so far today and trades a touch over a million shares daily on average. TAT shares are taking a tumble this morning after news that the company’s president and COO resigned. The company has a market cap of 460.82 million.

Zynga, Inc. (NASDAQ:ZNGA) is down 8.63% this morning at $8.05. ZNGA has traded 4.6 million shares today and trades 13.8 million shares a day on average. ZNGA shares have fallen steadily over the past week from around $9.60 to a low of just under $8 today. The company has a market cap of 5.64 billion.

CareFusion Corporation (NYSE:CFN) is down 9.11% today at $23.15. CFN has traded 3.9 million shares so far today, more than double its daily average. CFN shares are down this morning after the company lowered its bottom range of profit for their second quarter. The company has a market cap of 5.24 billion.