Websense Inc (Nasdaq:WBSN), Orexigen Therapeutics Inc (Nasdaq:OREX) and Pzena Investment Management Inc (Nasdaq:PZN) are among the biggest percentage losers in Wednesday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Kohlberg Capital Corp (Nasdaq:KCAP), Greenbrier Companies Inc (Nasdaq:GBX), Geokinetics Inc (Nasdaq:GOK), Olympic Steel Inc (Nasdaq:ZEUS), Startek, Inc (Nasdaq:SRT) and American Dairy Inc (Nasdaq:ADY).

Acura Pharmaceuticals Inc. (Nasdaq:ACUR), Halozyme Therapeutics Inc. (Nasdaq:HALO) and Actuant Corp. (Nasdaq:ATU) are among the biggest percentage losers in Tuesday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Heritage Financial Group (Nasdaq:HBOS), Pzena Investment Management Inc. (Nasdaq:PZN), Smith & Wesson Holding Corp. (Nasdaq:SWHC), Cytec Industries Inc. (Nasdaq:CYT), Hexcel Corp. (Nasdaq:HXL) and American Dental Partners Inc. (Nasdaq:ADPI).

Teekay Tankers Ltd. (Nasdaq:TNK), A Power Energy Generation Systems Ltd. (Nasdaq:APWR) and BNC Bancorp (Nasdaq:BNCN) are among the biggest percentage losers in Friday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Chindex International Inc. (Nasdaq:CHDX), Alyst Acquisition Corp. (Nasdaq:AYA), Citi Trends Inc. (Nasdaq:CTRN), Valhi Inc. (Nasdaq:VHI), Matrixx Initiatives (Nasdaq:MTXX) and Pzena Investment Management Inc. (Nasdaq:PZN).

Federal Agricultural Mortgage Corp. (Nasdaq:AGM), Trico Bancshares (Nasdaq:TCBK) and Ambac Financial Group (Nasdaq:AKT) are among the biggest percentage losers in Monday's trading among companies with market capitalizations under $1 billion.

Also included among the results: MGIC Investment Corp. (Nasdaq:MTG), Frontier Financial Corp. (Nasdaq:FTBK), MF Global Ltd. (Nasdaq:MF), Pzena Investment Management Inc. (Nasdaq:PZN), Corus Bankshares Inc. (Nasdaq:CORS) and CoBiz Financial Inc. (Nasdaq:COBZ).

Here are the biggest percentage losers among small caps:

eTelecare Global Solutions Inc. (Nasdaq:ETEL), Community Bancorp  (Nasdaq:CBON) and Radian Group Inc. (Nasdaq:RDN) are among the biggest percentage gainers in Friday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Imperial Capital Bancorp Inc. (Nasdaq:IMP), Dearborn Bancorp Inc. (Nasdaq:DEAR), First Regional Bancorp. (Nasdaq:FRGB), Pzena Investment Management Inc. (Nasdaq:PZN), Genesis Energy LP (Nasdaq:GEL) and City Bank (Nasdaq:CTBK).

Here are the biggest percentage gainers among small caps:

Protherics (Nasdaq:PTIL), Heelys Inc. (Nasdaq:HLYS) and Cheviot Financial Corp. (Nasdaq:CHEV) are among the biggest percentage gainers in Thursday's trading among companies with market capitalizations under $1 billion.   

Also included among the results: Deltek Inc. (Nasdaq:PROJ), Beazer Homes USA Inc. (Nasdaq:BZH), Noble International (Nasdaq:NOBL), Orexigen Therapeutics Inc. (Nasdaq:OREX), Pzena Investment Management Inc. (Nasdaq:PZN) and Ceco Environmental Corp. (Nasdaq:CECE). 

Here are the biggest percentage gainers among small caps:    

ILOG ADR (Nasdaq:ILOG), Headwaters Inc (Nasdaq:HW) and Gevity HR Inc (Nasdaq:GVHR) are among the biggest percentage gainers in Tuesday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Pzena Investment Management Inc (Nasdaq:PZN), UAL Corp (Nasdaq:UAUA), Modine Manufacturing Co (Nasdaq:MOD), ArvinMeritor Inc (Nasdaq:ARM), Meritage Homes Corp (Nasdaq:MTH) and Stepan Co (Nasdaq:SCL).

Here are the biggest percentage gainers among small caps:

Pzena Investment Management Inc. (NYSE:PZN) has gained 19% today after analysts at Keefe, Bruyette and Woods upgraded the company to “market perform” from “underperform.” The New York-based investment management firm is set to report its earnings on July 30, with analysts expecting earnings per share of $0.12 on revenues of $27.2 million

In today’s trading, shares are at $7.92 at 2:24 p.m. ET, up $1.28 from Monday’s close. During the past year, shares have ranged from $5.69 to $22.25.

Catalyst Semiconductor Inc (Nasdaq:CATS), MGIC Investment Corp (Nasdaq:MTG) and Cheviot Financial Corp (Nasdaq:CHEV) are among the biggest percentage gainers in Thursday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Gencor Industries Inc (Nasdaq:GENC), Provident Bankshares Corp (Nasdaq:PBKS), Atlantic Coast Federal Corp (Nasdaq:ACFC), USA Truck Inc (Nasdaq:USAK), Pzena Investment Management Inc (Nasdaq:PZN) and HNI Corp (Nasdaq:HNI).

Here are the biggest percentage gainers among small caps:

Community Valley Bancorp (CA) (Nasdaq:CVLL), Pzena Investment Management Inc (Nasdaq:PZN) and DineEquity Inc (Nasdaq:DIN) are among the biggest percentage losers in Friday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Gateway Financial Holdings Inc (Nasdaq:GBTS), Webster Financial Corp (Nasdaq:WBS), Alaska Air Group Inc (Nasdaq:ALK), FCStone Group, Inc. (Nasdaq:FCSX), Pacific Sunwear of California Inc (Nasdaq:PSUN) and Continental Airlines Inc (Nasdaq:CAL).

Here are the biggest percentage losers among small caps:

Royale Energy Inc (Nasdaq:ROYL), Jazz Pharmaceuticals Inc (Nasdaq:JAZZ) and Manitex International Inc (Nasdaq:MNTX) are among the biggest percentage gainers in Tuesday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Pzena Investment Management Inc (Nasdaq:PZN), AspenBio Pharma Inc (Nasdaq:APPY), Cytori Therapeutics Inc (Nasdaq:CYTX), IXYS Corp (Nasdaq:IXYS), FieldPoint Petroleum Corp (Nasdaq:FPP) and Torch Energy Royalty Trust (Nasdaq:TRU).

Here are the biggest percentage gainers among small caps:

Taylor Capital Group Inc (Nasdaq:TAYC), United Community Bancorp (Nasdaq:UCBA) and Syms Corp (Nasdaq:SYMS) are among the biggest percentage losers in Monday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Jazz Pharmaceuticals Inc (Nasdaq:JAZZ), Pzena Investment Management Inc (Nasdaq:PZN), MBT Financial Corp (Nasdaq:MBTF), Peerless Manufacturing Co (Nasdaq:PMFG), Washington Banking Co (Nasdaq:WBCO) and Community Partners Bancorp (Nasdaq:CPBC).

Here are the biggest percentage losers among small caps:

Shares of Pzena Investment Management (NYSE: PZN) are losing ground today after JP Morgan initiated coverage on the investment manager with a rating of “underweight.”

“Pzena is suffering significant underperformance that could lead to meaningful redemptions,” JP Morgan analyst Kenneth Worthington wrote in a research note today.

According to Worthington, Pzena funds have trailed benchmarks significantly in recent months. The investment manager has substantial positions in the financial sector, (40% according to Worthington), which has caused the company pain the past few months as the credit crisis has crippled that sector. The analyst said he thinks the firm’s funds’ performance will show even greater deterioration in the fourth quarter of 2007 due to large positions held in Citigroup (down 39% YTD), Fannie Mae (down 39%), and Freddie Mac (down 51%).

Additionally, outflows are accelerating for Pzena’s $8.1 billion sub-advised fund for John Hancock, according to the analyst.

Due to challenging market conditions, deep value investing may be returning to favor, according to Worthington, which could bode well for this small cap. However, the analyst says weak returns could “test the mettle” of institutional investors.

“We are impressed with the rigor of Pzena's investment method and with the quality of employees," Worthington wrote in a research note today. “We believe that the current setbacks are temporary, but could negatively impact the stock in the near to intermediate term.”

Shares of Pzena (PZN) slid 3.41%, or $0.44, to $12.46 at 2:02 p.m. ET. Shares of Pzena have been trading in the range of $10.55 to $22.25 for the past 52 weeks.

Simulations Plus, Inc. (AMEX: SLP), Santander BanCorp (NYSE: SBP) and Medivation, Inc. (Nasdaq: MDVN) are among the biggest percentage losers in Monday's trading among companies with market capitalizations under $750 million.

Here are today's biggest percentage losers: