RadNet (RDNT) had the highest return in April 2014 by a US stock with a market cap of $300M+, returning 73.2%.

ASSET	MONTH	% RETURN
RadNet (RDNT)	April 2014	73.17%
Sarepta Therapeutics (SRPT)	April 2014	53.05%
OneSpan (OSPN)	April 2014	50.53%
Byrna Technologies (BYRN)	April 2014	33.33%
Cresud SACIF y A (CRESY)	April 2014	29.78%
Tiptree (TIPT)	April 2014	28.21%
Pampa Energia SA ADR (PAM)	April 2014	26.5%
Red Cat (RCAT)	April 2014	25%
Akebia Ther (AKBA)	April 2014	23.77%
IRSA Inversiones Y Representaciones (IRS)	April 2014	23.63%
Myriad Genetics (MYGN)	April 2014	23.57%
Repligen (RGEN)	April 2014	22.96%
Prestige Brand (PBH)	April 2014	22.78%
Zillow (ZG)	April 2014	22.76%
JAKKS Pacific (JAKK)	April 2014	21.5%
Comstock Resources (CRK)	April 2014	21.24%
AstraZeneca PLC ADR (AZN)	April 2014	21.19%
Weatherford International (WFRD)	April 2014	20.69%
Maui Land & Pineapple (MLP)	April 2014	20.46%
Weibo (WB)	April 2014	20.22%
Centrais Electricas Brasileiras (EBR)	April 2014	19.66%
PBF Energy (PBF)	April 2014	19.03%
Sibanye Gold Ltd ADR (SBSW)	April 2014	19.01%
DXP Enterprises (DXPE)	April 2014	18.96%
Sunoco (SUN)	April 2014	18.87%