Abivax SA American Depositary Shares (ABVX) had the highest return in July 2025 by a mid-cap US stock, returning 816.6%.

ASSET	MONTH	% RETURN
Abivax SA American Depositary Shares (ABVX)	July 2025	816.6%
Opendoor Technologies (OPEN)	July 2025	243.93%
Celcuity LLC (CELC)	July 2025	187.98%
MP Materials (MP)	July 2025	85.58%
Kodiak Sciences (KOD)	July 2025	76.75%
CECO Environmental (CECO)	July 2025	59.06%
Cogent Biosciences (COGT)	July 2025	59.05%
Joby Aviation (JOBY)	July 2025	58.67%
Energy Fuels (UUUU)	July 2025	56.45%
Liquidia Technologies (LQDA)	July 2025	50.36%
Iovance Biotherapeutics (IOVA)	July 2025	49.42%
Impinj (PI)	July 2025	40.76%
Nio Inc Class A ADR (NIO)	July 2025	40.35%
Oklo (OKLO)	July 2025	39.51%
Definium Therapeutics (DFTX)	July 2025	39.42%
Modine Manufacturing (MOD)	July 2025	38.41%
Cleveland-Cliffs (CLF)	July 2025	38.06%
Indivior PLC Ordinary Shares (INDV)	July 2025	37.79%
Rush Street Interactive (RSI)	July 2025	36.03%
Hims Hers Health (HIMS)	July 2025	35.5%
Rhythm Pharmaceuticals (RYTM)	July 2025	35.16%
Materion (MTRN)	July 2025	34.31%
Bel Fuse B (BELFB)	July 2025	33.82%
Aehr Test Systems (AEHR)	July 2025	33.49%
Abcellera Biologics (ABCL)	July 2025	32.25%

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