Soleno Therapeutics (SLNO) had the highest return in Q1 2015 by a US stock with a market cap of $1B+, returning 344.4%.

ASSET	QUARTER	% RETURN
Soleno Therapeutics (SLNO)	Q1 2015	344.44%
Celsius (CELH)	Q1 2015	149.97%
Quantum Computing (QUBT)	Q1 2015	141.67%
Travere Therapeutics (TVTX)	Q1 2015	94.32%
Corcept Therapeutics (CORT)	Q1 2015	86.05%
Ocular Therapeutix (OCUL)	Q1 2015	78.58%
Neurocrine Biosciences (NBIX)	Q1 2015	75.79%
Pampa Energia SA ADR (PAM)	Q1 2015	75.47%
Exelixis (EXEL)	Q1 2015	74.83%
Empresa Distribuidora y Comercializadora Norte SA ADR (EDN)	Q1 2015	70.64%
Applied Digital (APLD)	Q1 2015	70.1%
Universal Display (OLED)	Q1 2015	67.14%
Wayfair (W)	Q1 2015	60.68%
Sharplink Gaming (SBET)	Q1 2015	59.6%
Barrett Business Services (BBSI)	Q1 2015	57.1%
Insperity (NSP)	Q1 2015	54.08%
Repligen (RGEN)	Q1 2015	53.1%
Vipshop (VIPS)	Q1 2015	52.86%
Transportadora de Gas del Sur SA ADR (TGS)	Q1 2015	52.72%
Celldex Therapeutics (CLDX)	Q1 2015	51.39%
BBVA Banco Frances SA ADR (BBAR)	Q1 2015	48.84%
Amneal Pharmaceuticals, Inc Class A Common Stock (AMRX)	Q1 2015	46.56%
Halozyme Therapeutics (HALO)	Q1 2015	46.16%
Grupo Financiero Galicia SA ADR (GGAL)	Q1 2015	46.06%
Ambarella (AMBA)	Q1 2015	45.6%