WM Technology (MAPSW) had the best day in December 2022 by a mid-cap US stock on December 9, 2022, returning 87.9%.

ASSET	DATE	% RETURN
WM Technology (MAPSW)	12/9/2022	87.93%
SoundHound AI (SOUN)	12/30/2022	75.25%
Soleno Therapeutics (SLNO)	12/19/2022	66.67%
Advantage Solutions (ADVWW)	12/23/2022	35.75%
Viking Therapeutics (VKTX)	12/19/2022	28.26%
Soleno Therapeutics (SLNO)	12/27/2022	26.17%
Verona Pharma PLC ADR (VRNA)	12/21/2022	24.52%
Advantage Solutions (ADVWW)	12/9/2022	24.13%
Advantage Solutions (ADVWW)	12/19/2022	21.43%
TAL Education (TAL)	12/20/2022	19.61%
Bilibili (BILI)	12/2/2022	19.45%
Iris Energy (IREN)	12/30/2022	19.05%
Rhythm Pharmaceuticals (RYTM)	12/12/2022	18.7%
WM Technology (MAPSW)	12/28/2022	18%
TMC the metals (TMC)	12/29/2022	17.1%
Kingsoft Cloud Holdings (KC)	12/2/2022	16.84%
RLX Technology (RLX)	12/2/2022	16.52%
WM Technology (MAPSW)	12/29/2022	16.4%
Atour Lifestyle Holdings Limited American Depositary Shares (ATAT)	12/2/2022	16.23%
Madrigal Pharmaceuticals (MDGL)	12/21/2022	15.77%
Madrigal Pharmaceuticals (MDGL)	12/19/2022	15.69%
Peloton Interactive (PTON)	12/2/2022	15.65%
GDS (GDS)	12/2/2022	15.42%
Ast Spacemobile (ASTS)	12/29/2022	15.16%
Immunitybio (IBRX)	12/12/2022	14.36%

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