Weatherford International (WFRD) had the best month between 2019 and 2023 by a mid-cap US stock in December 2019, returning 120,172.8%.

ASSET	MONTH	% RETURN
Weatherford International (WFRD)	December 2019	120,172.81%
Weatherford International (WFRD)	May 2019	11,300%
Trump Media & Technology (DJTWW)	October 2021	6,617.39%
Inventrust Properties (IVT)	September 2021	1,456.72%
Ondas (ONDS)	November 2020	698.02%
Trump Media & Technology (DJT)	October 2021	577.5%
Soleno Therapeutics (SLNO)	September 2023	494.96%
Cogent Biosciences (COGT)	July 2020	484.91%
Pagaya Technologies (PGY)	July 2022	460.27%
Applied Digital (APLD)	April 2021	417.24%
BigBearai (BBAI)	January 2023	356.7%
Antero Resources (AR)	April 2020	325.71%
Madrigal Pharmaceuticals (MDGL)	December 2022	311%
Kinetik (KNTK)	November 2020	302.47%
Quantumscape (QS)	November 2020	293.96%
Regencell Bioscience (RGC)	August 2021	278.36%
WM Technology (MAPSW)	December 2020	276.44%
Sezzle (SEZL)	August 2023	257.97%
SM Energy (SM)	April 2020	251.23%
Mirum Pharmaceuticals (MIRM)	December 2019	235.43%
APA (APA)	April 2020	224.72%
Globalstar, Inc Common Stock (GSAT)	January 2021	218.18%
VinFast Auto Ltd Ordinary Shares (VFS)	August 2023	212.7%
Bitfarms (BITF)	December 2020	209.45%
Rhythm Pharmaceuticals (RYTM)	July 2022	208.82%

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