Tango Therapeutics (TNGX) had the highest return in September 2023 by a small-cap US stock, returning 73.8%.

ASSET	MONTH	% RETURN
Tango Therapeutics (TNGX)	September 2023	73.77%
Cybin (CYBN)	September 2023	71.42%
Getty Images (GETY)	September 2023	46.17%
Owlet (OWLT)	September 2023	44.52%
Biohaven Pharmaceutical (BHVN)	September 2023	41.21%
Matrix Service (MTRX)	September 2023	40.14%
Ramaco Resources (METC)	September 2023	40%
Natural Gas Services (NGS)	September 2023	31.41%
Hallador Energy (HNRG)	September 2023	31.33%
Rocket Pharmaceuticals (RCKT)	September 2023	29.52%
KNOT Offshore Partners (KNOP)	September 2023	28.14%
MillerKnoll (MLKN)	September 2023	27.48%
G-III Apparel (GIII)	September 2023	25.1%
IperionX Limited American Depositary Share (IPX)	September 2023	24.78%
Canopy Growth (CGC)	September 2023	24.29%
Groupon (GRPN)	September 2023	23.65%
IsoEnergy (ISOU)	September 2023	22.79%
Heritage Insurance Hldgs (HRTG)	September 2023	22.68%
Natural Resource Partners (NRP)	September 2023	20.95%
Northern Dynasty Minerals (NAK)	September 2023	20.94%
MSC Income Fund (MSIF)	September 2023	20.8%
Designer Brands (DBI)	September 2023	19.77%
Ranger Energy Services (RNGR)	September 2023	19.46%
Talkspace (TALK)	September 2023	18.9%
Akso Health Group ADR (AHG)	September 2023	17.62%

Small-cap stocks are treated as having a market cap between $300M and $2B.