The filings follow a sensational run in the past week for Cardica's stock, which has jumped more than 50% since closing at $2.42 last Thursday. The shares rose almost 18% on Wednesday alone to finish at $3.84, making for year-to-date appreciation of 180%. Volume has soared along with the share price as trading has exceeded at least 300,000 in the past four sessions vs. the issue's three-month trailing daily average of around 50,000. The driver for the recent buying interest was a strong recommendation from Wedbush Morgan. which initiated coverage of the stock with an outperform rating. The firm's bullish thesis is based on its enthusiasm for Cardica's Microcutter product, an endoscopic stapling device that's still in clinical development. In its note to clients about Cardica, Wedbush did note the company would likely need to bulk up its balance sheet. The company's cash balance stood at around $15 million at the end of September, an amount that the firm estimated would be enough to fund operations through the development and initial launch of Microcutter, which is expected to occur in the the company's fiscal 2012 first quarter ending in September. "