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

  • ProShares Trust Ultra VIX Short Term Futures ETF (UVXY) opened at $7.59 after closing the previous trading session at $8.64, gapping down. The stock price is down 12% with a volume of 5.1 million.

  • With an opening price of $36.51, ACI Worldwide (ACIW) gapped down from its previous close of $43.43. Shares are down 11.8%, trading at a volume of 344,260. Shares are down $6.61 (-14.7%) from a price of $44.91 on July 19, 2012. The stock has moved down across its 50-day moving average of $43.11 today.

  • 3D Systems Corporation (DDD) gapped down today, opening at $30.40 after closing the previous trading session at $34.29. Shares are trading at a volume of 341,289 at a price decrease of 2.4%. Over the last three months, the stock has gained $3.98 (13.5%) from a price of $29.49 on April 30, 2012. The stock has dropped a step closer to its 50-day moving average, sitting just 1% above the mark.

  • Ruby Tuesday (RT) opened at $5.14, gapping down from its previous close of $6.17. While trading at a volume of 384,172, the stock price has fallen 14.1%. Shares are down over the last two months as the price has dropped $2 (-27.4%) from a price of $7.30 on May 29, 2012. The stock is trading at 76.7% of its 50-day moving average and 72.9% of its 200-day moving average.