Northern Oil & Gas (NOG) had the highest return between 2007 and 2011 by a mid-cap US stock, returning 7,735,369.2%.

ASSET	YEARS	% RETURN
Northern Oil & Gas (NOG)	2007-2011	7,735,369.23%
Sandstorm Gold Ltd N (SAND)	2007-2011	961,683.33%
Aris Mining (ARMN)	2007-2011	41,528.42%
Weatherford International (WFRD)	2007-2011	9,900%
Amneal Pharmaceuticals, Inc Class A Common Stock (AMRX)	2007-2011	706.8%
Perrigo (PRGO)	2007-2011	476.67%
Golar LNG (GLNG)	2007-2011	447.86%
ICL Israel Chemicals (ICL)	2007-2011	400.82%
Cal-Maine Foods (CALM)	2007-2011	360.01%
Mesoblast (MESO)	2007-2011	347.29%
PriceSmart (PSMT)	2007-2011	307.56%
First Majestic Silver (AG)	2007-2011	270.11%
Balchem (BCPC)	2007-2011	268.44%
NewMarket (NEU)	2007-2011	258.71%
Ultrapar Participacoes SA ADR (UGP)	2007-2011	244.58%
Dorman Products (DORM)	2007-2011	241.32%
Travere Therapeutics (TVTX)	2007-2011	233.33%
Chart Industries (GTLS)	2007-2011	229.09%
Fortuna Silver Mines (FSM)	2007-2011	217.34%
Bausch Health Companies (BHC)	2007-2011	214.32%
Pegasystems (PEGA)	2007-2011	207.54%
Boston Beer (SAM)	2007-2011	202.14%
Alliance Resource Partners (ARLP)	2007-2011	201.16%
BRF SA ADR (BRFS)	2007-2011	201%
Hawkins (HWKN)	2007-2011	198.67%

Mid-cap stocks are treated as having a market cap between $2B and $10B.