Alpha Metallurgical Resources (AMR) had the highest return between 2021 and 2022 by a mid-cap US stock, returning 1,245%.

ASSET	YEARS	% RETURN
Alpha Metallurgical Resources (AMR)	2021-2022	1,245.02%
Peabody Energy (BTU)	2021-2022	973.99%
Consol Energy (CEIX)	2021-2022	829.62%
Weatherford International (WFRD)	2021-2022	757.96%
Baytex Energy (BTE)	2021-2022	719.98%
Vista Oil Gas ADR (VIST)	2021-2022	504.63%
PBF Energy (PBF)	2021-2022	469.62%
SM Energy (SM)	2021-2022	467.1%
Catalyst Pharmaceuticals (CPRX)	2021-2022	458.56%
Dillards (DDS)	2021-2022	455.16%
Alliance Resource Partners (ARLP)	2021-2022	404.76%
Scorpio Tankers (STNG)	2021-2022	394.65%
Chord Energy (CHRD)	2021-2022	378.29%
Matador Resources (MTDR)	2021-2022	368.8%
Tecnoglass (TGLS)	2021-2022	352.77%
Avis Budget (CAR)	2021-2022	334.71%
Torm PLC Class A (TRMD)	2021-2022	323.75%
Tidewater (TDW)	2021-2022	319.23%
Globalstar (GSAT)	2021-2022	299.52%
Arch Resources (ARCH)	2021-2022	279.68%
Lantheus (LNTH)	2021-2022	277.2%
Verona Pharma PLC ADR (VRNA)	2021-2022	270.64%
EnLink Midstream LLC (ENLC)	2021-2022	269.99%
Murphy Oil (MUR)	2021-2022	267.67%
Range Resources (RRC)	2021-2022	265.68%

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