NEW YORK ( TheStreet) -- TiVo ( TIVO) was one of several stocks trading near $5 were moving on above-average volume Wednesday following a ruling by the U.S. Patent and Trademark Office against the digital video recorder maker. TiVo shares tumbled after the U.S. Patent and Trademark Office ruled Tuesday in favor of Dish Network ( DISH) and EchoStar ( SATS) in a patent claim case where TiVo claimed both companies infringed on its "time warp" patent. TiVo shares slid by 47 cents, or 6.2%, to $7.22, extending Tuesday's 5.5% decline. Volume topped 6.11 million shares, compared to the 50-day average daily volume of 5.43 million, according to the Nasdaq. Elsewhere, Cereplast ( CERP) rallied by 87 cents, or 21.5%, to $4.92 after the bioplastics manufacturer said it expects to ship 16 million pounds of bio-plastic resins in 2010, quadrupling year-ago shipments. Volume topped 295,000 shares, compared to the average daily volume of 32,000. American Capital ( ACAS) jumped by 52 cents, or 12%, to $4.86 after the company extended its debt-exchange offer by one day to June 9. American Capital needs approval from 85% of its noteholders for its plan to restructure debt, although only 14% of participating noteholders supported the company's plan. Volume topped 8.16 million shares, compared to the 50-day average daily volume of 9.63 million. Ambac Financial ( ABK) plunged by 36 cents, or 33.6%, to 71 cents after the bond insurer said in a regulatory filing that it may seek a negotiated restructuring through a prepackaged bankruptcy. In addition, senior debtholders of the company have formed a committee to nudge Ambac toward a prepackaged bankruptcy plan, Reuters reports, citing people familiar with the matter. Volume topped 54 million shares, compared to the three-month average daily volume of 55.46 million, according to Yahoo! Finance. -- Written by Robert Holmes in Boston. Check out all of Monday's high-volume, under-$5 stocks at the Dollar Store. View the Dollar Store portfolio on StockPickr. Follow Robert Holmes on Twitter and become a fan of TheStreet.com on Facebook.