ViroPharma Inc. (Nasdaq:VPHM), P.F. Chang's China Bistro Inc. (Nasdaq:PFCB) and Sequenom Inc. (Nasdaq:SQNM) are among the most actively traded companies in Wednesday's trading among companies with market capitalizations under $1 billion.

Also included among the results: Exelixis Inc. (Nasdaq:EXEL), Jazz Pharmaceuticals Inc. (Nasdaq:JAZZ), CardioNet Inc. (Nasdaq:BEAT), JAKKS Pacific Inc. (Nasdaq:JAKK), Energy Conversion Devices Inc. (Nasdaq:ENER) and THQ Inc. (Nasdaq:THQI).

Here are the most actively traded companies among small caps:

		Price at 9:08 ET	Change	% Change	Volume	Year High	Year Low
VPHM	VIROPHARMA INC	8.31	+1.41	+20.4%	188.5k	15.16	3.79
PFCB	P F CHANGS CHINA BISTRO INC	33.66	+0.00	+0.0%	67.2k	36.25	14.51
SQNM	SEQUENOM INC	6.02	-0.07	-1.1%	48.0k	29.14	2.86
EXEL	EXELIXIS INC	6.10	+0.23	+3.9%	39.9k	7.35	2.11
JAZZ	JAZZ PHARMACEUTICALS INC	6.50	-0.08	-1.2%	23.7k	8.85	0.52
BEAT	CARDIONET INC	7.05	-0.25	-3.4%	22.1k	35.89	5.60
JAKK	JAKKS PAC INC	10.40	-1.30	-11.1%	22.0k	27.12	10.17
ENER	ENERGY CONVERSION DEVICES IN	15.32	+0.26	+1.7%	18.4k	83.20	11.83
THQI	THQ INC	7.55	-0.86	-10.2%	15.7k	17.14	2.23
CSIQ	CANADIAN SOLAR INC	14.59	-0.31	-2.1%	13.1k	33.24	3.00