This week's biggest % winners & losers : May 16 - 20, 16 (wk 20)

The following are this week's top 20 percentage gainers and top 20 percentage losers, categorized by sectors (over $300 mln market cap and 100K average daily volume).

This week's top 20 % gainers

• Healthcare:ANAC (99.66 +55.65%),ONCE (50.84 +51.72%),MGNX (22.61 +30.02%),CHRS (19.5 +28.04%),CFMS (6.49 +26.76%),RPTP (5.2 +22.35%),SGYP (3.26 +22.1%),PBYI (31.95 +21.9%),ACAD (34.04 +21.1%),MCRB (28.9 +21.07%),CTLT (28.65 +20.13%),HRTX (19.47 +19.23%),AMPH (15.43 +18.88%),NVAX (5.24 +18.82%)
• Energy:IOC (43.57 +41.23%),LINE (0.16 +29.17%),GPRE (17.76 +20.49%),TEGP(25.75 +19.99%)
• Consumer Staples:ANDE (34.22 +30.11%)
• Telecommunication Services:SAAS (13.86 +45.28%)

This week's top 20 % losers

• Healthcare:GEN (1.65 -17.91%)
• Materials:ATI (11.23 -20.69%),TROX (4.48 -13.35%),SID (2.08 -12.97%),GGB (1.62 -12.43%)
• Consumer Discretionary:FRAN (10.56 -29.03%),RRGB (48.39 -21.23%),VIPS (10.49 -12.58%)
• Information Technology:CMCM (10.2 -28.42%),RENN (2.06 -17.6%),BITA (18.62 -13.15%),OCLR (4.37 -12.77%),ACXM (19.99 -12.52%)
• Financials:OCN (1.59 -20.9%)
• Energy:PWE (0.69 -15.86%),TNK (3.38 -14.43%),WFT (4.94 -12.41%)
• Consumer Staples:STKL (3.75 -15.73%), HRL (34.86 -12.63%)
• Utilities:CIG (1.52 -12.14%)