Madrigal Pharmaceuticals (MDGL) had the best month in 2022 by a mid-cap US stock in December 2022, returning 311%.

ASSET	MONTH	% RETURN
Madrigal Pharmaceuticals (MDGL)	December 2022	311%
Rhythm Pharmaceuticals (RYTM)	July 2022	208.82%
Akero Therapeutics (AKRO)	September 2022	183.99%
Biohaven Pharmaceutical (BHVN)	October 2022	159.31%
Advantage Solutions (ADVWW)	August 2022	141.33%
Marathon Digital (MARA)	July 2022	140.11%
Wave Life Sciences (WVE)	June 2022	135.51%
Viking Therapeutics (VKTX)	December 2022	131.53%
F&G Annuities & Life (FG)	November 2022	129.9%
Advantage Solutions (ADVWW)	October 2022	129.77%
Miniso Group Holding (MNSO)	November 2022	117.1%
Canoo (GOEVW)	July 2022	108.33%
Belite Bio Inc ADR (BLTE)	June 2022	105.54%
Verona Pharma PLC ADR (VRNA)	December 2022	101.62%
Applied Blockchain (APLD)	July 2022	98.13%
Immunovant (IMVT)	October 2022	97.53%
VEON (VEON)	November 2022	92.25%
Avidity Biosciences (RNA)	December 2022	90.47%
Lantheus (LNTH)	February 2022	87.46%
Verona Pharma PLC ADR (VRNA)	August 2022	83.77%
WM Technology (MAPSW)	March 2022	83.33%
Nuvalent (NUVL)	October 2022	82.57%
Polestar Automotive Holding UK PLC Class C-1 ADS (ADW) (PSNYW)	November 2022	81.97%
Rhythm Pharmaceuticals (RYTM)	August 2022	81.53%
Bilibili (BILI)	November 2022	77.51%

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