Arrowhead Pharmaceuticals (ARWR) has had the highest return this month by a mid-cap US stock, returning 24.3%.

ASSET	MONTH	% RETURN
Arrowhead Pharmaceuticals (ARWR)	December 2025	24.26%
Vera Therapeutics (VERA)	December 2025	23.64%
Lumen Technologies (LUMN)	December 2025	20.38%
Sitime (SITM)	December 2025	19.64%
American Eagle Outfitters (AEO)	December 2025	17.9%
Rumble (RUM)	December 2025	17.59%
Saia (SAIA)	December 2025	17.46%
TMC the metals (TMC)	December 2025	16.79%
Alpha Metallurgical Resources (AMR)	December 2025	15.46%
Central Puerto (CEPU)	December 2025	15.21%
Genius Sports (GENI)	December 2025	14.92%
Asana (ASAN)	December 2025	14.43%
Solaris Energy Infrastructure (SEI)	December 2025	14.07%
Plug Power (PLUG)	December 2025	14.07%
D-Wave Quantum (QBTS)	December 2025	13.95%
Applied Digital (APLD)	December 2025	13.34%
Ondas (ONDS)	December 2025	13.2%
Regencell Bioscience (RGC)	December 2025	13.03%
Diodes (DIOD)	December 2025	12.81%
Atour Lifestyle Holdings Limited American Depositary Shares (ATAT)	December 2025	12.69%
Camtek (CAMT)	December 2025	12.64%
CSW Industrials (CSW)	December 2025	12.49%
Schneider National (SNDR)	December 2025	12.47%
Vishay Intertechnology (VSH)	December 2025	12.2%
CAVA (CAVA)	December 2025	11.52%

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