Here’s what’s hot in the market today: APAC soared after One Equity Partners moved to acquire the company. Lumber Liquidators, Bebe Stores, and Natus Medical all fell on reports of poor earnings. Hi-Tech Pharmacal, however, rose thanks to strong earnings.

APAC Customer Services (NASDAQ: APAC) leapt almost 55% on huge volume as One Equity Partners said it would acquire the company for $470 million. Shareholders in the customer service company would receive $8.55 per share. APAC was trading around $8.44.

Lumber Liquidators (NYSE: LL) dropped more than 23% after it lowered its outlook for both the second and third quarters of 2011. Poor promotional sales and high transportation costs led the hardwood flooring company to project sales of between $670 and $700 million for the second quarter, down from the $730 million projected just last April. LL shares were trading under $20.

Hi-Tech Pharmacal (NASDAQ: HITK), the prescription and over-the-counter drug manufacturer, rose almost 5% to top $30 after it  reported strong earnings for the quarter that ended April 30. Sales totaled more than $57 million, a 45% increase from the same period in 2010.

Bebe Stores (NASDAQ: BEBE) rose almost 17% as the clothing and accessories retailer reported earnings for its fiscal fourth quarter. Sales from continuing operations totaled more than $122 million, a year-on-year increase of more than 7%. Shares were trading near $8.

Natus Medical (NASDAQ: BABY) fell close to 9% to trade around $14.25. Specializing in healthcare technology for treating infants, Natus Medical is having a rough 2011. The company lowered its revenue guidance for the second quarter to $58 million, well below analyst expectations of between $62 and $64 million.

As of this writing, Anthony John Agnello did not own a position in any of the stocks named here. Follow him on Twitter at @ajohnagnello and become a fan of InvestorPlace on Facebook.