Integra Resources (ITRG) had the highest return between 2020 and 2021 by a small-cap US stock, returning 358,233.3%.

ASSET	YEARS	% RETURN
Integra Resources (ITRG)	2020-2021	358,233.33%
HIVE Blockchain Technologies (HIVE)	2020-2021	3,541.38%
Novavax (NVAX)	2020-2021	3,485.71%
Celldex Therapeutics (CLDX)	2020-2021	1,625%
Bit Digital (BTBT)	2020-2021	1,500%
Standard Lithium (SLI)	2020-2021	1,419.52%
A2Z Smart Technologies (AZ)	2020-2021	1,358%
Bitfarms (BITF)	2020-2021	1,221.99%
Aehr Test Systems (AEHR)	2020-2021	1,109%
NRx Pharmaceuticals (NRXPW)	2020-2021	1,101.3%
Kopin (KOPN)	2020-2021	897.56%
IsoEnergy (ISOU)	2020-2021	878.44%
Ocugen (OCGN)	2020-2021	863.98%
Lithium Argentina (LAR)	2020-2021	804.34%
Plug Power (PLUG)	2020-2021	779.44%
Digital Turbine (APPS)	2020-2021	745.91%
Owens & Minor (OMI)	2020-2021	739.36%
Beyond (BYON)	2020-2021	733.47%
Amark Preci (AMRK)	2020-2021	729.63%
Danaos (DAC)	2020-2021	727.67%
Real Brokerage (REAX)	2020-2021	711.17%
Atlanticus (ATLC)	2020-2021	701.35%
Sigma Lithium Resources (SGML)	2020-2021	700.77%
Intellia Therapeutics (NTLA)	2020-2021	699.46%
Fulgent Genetics (FLGT)	2020-2021	674.96%

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