QXO (QXO) had the highest return between 2012 and 2015 by a large-cap US stock, returning 6,137,800%.

ASSET	YEARS	% RETURN
QXO (QXO)	2012-2015	6,137,800%
Genmab A-S (GMAB)	2012-2015	1,949.24%
Netflix (NFLX)	2012-2015	1,039.24%
Alnylam Pharmaceuticals (ALNY)	2012-2015	1,030.13%
Regeneron Pharmaceuticals (REGN)	2012-2015	860.66%
Celsius (CELH)	2012-2015	823.86%
DexCom (DXCM)	2012-2015	760.29%
Ionis Pharmaceuticals (IONS)	2012-2015	742.59%
Tesla (TSLA)	2012-2015	729.35%
Incyte (INCY)	2012-2015	620.6%
Constellation Brands Inc Class A (STZ)	2012-2015	584.7%
Neurocrine Biosciences (NBIX)	2012-2015	547.25%
Delta Air Lines (DAL)	2012-2015	530.19%
Illumina (ILMN)	2012-2015	519.19%
Insmed (INSM)	2012-2015	481.73%
Tyler Technologies (TYL)	2012-2015	464.69%
NXP Semiconductors (NXPI)	2012-2015	433.91%
Builders FirstSource (BLDR)	2012-2015	427.62%
Broadcom (AVGO)	2012-2015	426.34%
Southwest Airlines (LUV)	2012-2015	407.17%
Gilead Sciences (GILD)	2012-2015	393.95%
Corpay (CPAY)	2012-2015	376.91%
Monolithic Power Systems (MPWR)	2012-2015	342.55%
Expedia (EXPE)	2012-2015	336.52%
NetEase (NTES)	2012-2015	328.48%

Large-cap stocks are treated as having a market cap of $10B+.