Editor's Note: In this feature from Stockpickr, we highlight lists of stocks that have made new highs, lows or seen other unusual activity.Biggest % Gainers: Dynacq Healthcare ( DYII) skyrocketed more than 200% Monday after the company posted spectacular third-quarter results that shattered estimates. The Houston health care company reported income of 16 cents a share, up from 3 cents a share a year earlier. The stock gained $5.14, to close Monday at $7.87. 52-Week Highs: Blue Nile ( NILE) hit a 52-week high of $81.75 after the online jewelry seller received a positive analyst report. Citibank upgraded NILE to buy from hold and upped its price target to $88. The company closed the day up $6.59, or 9.2%, at $78.56. Rising on Unusual Volume: Penford ( PENX) experienced heavy trading volume as the chemical company gained 2% Monday. The stock closed up 71 cents at $35.59. Biggest % Losers: Hudson Highland ( HHGP) was down more than 22% after the company cut its second-quarter revenue guidance. The New York staffing company slumped $4.95 to end the day at $17.07. 52-Week Lows: After First Albany downgraded Travelzoo ( TZOO) from buy to neutral, the stock sank to a 52-week low of $24.25. Travelzoo says its new business model will hurt near-term earnings. The online travel company closed down $2.15, or 8.1%, at $24.38. Stocks With Unusual Option Activity: SanDisk ( SNDK) experienced unusual options activity Monday as the company's chief operating officer exercised options. The Milpitas, Calif.-based company lost 58 cents, or 1.1%,to $54.18.