Netflix (NFLX) had the highest return between 2012 and 2015 by a US stock in the S&P 500 (GSPC), returning 1,039.2%.

ASSET	YEARS	% RETURN
Netflix (NFLX)	2012-2015	1,039.24%
Regeneron Pharmaceuticals (REGN)	2012-2015	860.66%
DexCom (DXCM)	2012-2015	760.29%
Tesla (TSLA)	2012-2015	729.35%
Incyte (INCY)	2012-2015	620.6%
Constellation Brands Inc Class A (STZ)	2012-2015	584.7%
Delta Air Lines (DAL)	2012-2015	530.19%
EPAM Systems (EPAM)	2012-2015	471.78%
Tyler Technologies (TYL)	2012-2015	464.69%
NXP Semiconductors (NXPI)	2012-2015	433.9%
Builders FirstSource (BLDR)	2012-2015	427.62%
Broadcom (AVGO)	2012-2015	426.31%
Southwest Airlines (LUV)	2012-2015	407.17%
Gilead Sciences (GILD)	2012-2015	393.95%
Corpay (CPAY)	2012-2015	376.91%
Skyworks Solutions (SWKS)	2012-2015	361.99%
Monolithic Power Systems (MPWR)	2012-2015	342.55%
Expedia (EXPE)	2012-2015	336.52%
Royal Caribbean Cruises (RCL)	2012-2015	317.06%
Huntington Ingalls Industries (HII)	2012-2015	311.93%
Smurfit WestRock (SW)	2012-2015	311.28%
Aptiv (APTV)	2012-2015	303.96%
Smith AO (AOS)	2012-2015	292.92%
HCA (HCA)	2012-2015	287.24%
Valero Energy (VLO)	2012-2015	286.29%