Aetna, H&R Block Among Stocks Gapping Down Thursday

Here are stocks that gapped down today with opening prices significantly lower than the previous trading day's close:

• After closing the previous trading session at $49.36, Aetna (NYSE:AET) gapped down with an opening price of $44.39. While trading at a volume of five million, the stock price has fallen 10.9%. The stock has seen some negative movement recently as shares are down $5.10 (-10.4%) from a price of $49.07 on April 19, 2012. The stock has dropped a step closer to its 200-day moving average, sitting just 0% above the mark.

• H&R Block (NYSE:HRB) opened at $14.42 after closing the previous trading session at $16.74, gapping down. Shares are trading at a volume of 4.4 million at a price decrease of 12.3%. The stock has been going in a negative direction over the last month, dropping $2.31 (-13.6%) from a price of $16.99 on March 27, 2012. The stock has moved down across its 50-day moving average of $16.72 today.

• Alcatel-Lucent (NYSE:ALU) gapped down today, opening at $1.69 after closing the previous trading session at $1.95. Shares are down 15.9%, trading at a volume of 38 million. The stock is trading at 75.5% of its 50-day moving average and 74.6% of its 200-day moving average.

• TriQuint Semiconductor (NASDAQ:TQNT) opened at $4.81, gapping down from its previous close of $5.52. Shares have dropped 4.9%, trading at a volume of 8.1 million. The share price has been dipping in the last month, down $1.60 (-23.4%) from $6.85 on March 27, 2012. The stock is trading at 85.9% of its 50-day moving average and 89.2% of its 200-day moving average.

• MetroPCS Communications (NYSE:PCS) opened at $6.81 after closing the previous trading session at $7.94, gapping down. While trading at a volume of 5.8 million, the stock price has fallen 11.1%. The stock is trading at 78.1% of its 50-day moving average and 77% of its 200-day moving average.

• Novacea (NASDAQ:TSPT) gapped down today, opening at $9.60 after closing the previous trading session at $11. Shares are down 13.7%, trading at a volume of 715,619. The stock has risen $1.50 (18.8%) over the last three months from a price of $7.99 on January 30, 2012. The stock is trading 12.1% above its 200-day moving average.

• AXT (NASDAQ:AXTI) opened at $5.45 after closing the previous trading session at $6.07, gapping down. The stock price is down 15.2% with a volume of 262,949. The share price has dropped $1.50 (-22.6%) from $6.65 on March 27, 2012. The stock has moved down across its 50-day moving average of $6.05 today.

• With an opening price of $1.29, ACADIA Pharmaceuticals (NASDAQ:ACAD) gapped down from its previous close of $1.49. Shares have dropped 4.7%, trading at a volume of 263,132. The stock is trading at 80.5% of its 50-day moving average and 95.2% of its 200-day moving average.

• After closing the previous trading session at $2.80, Lantronix (NASDAQ:LTRX) gapped down with an opening price of $2.40. Shares are down 13.6%, trading at a volume of 105,086.