Inventrust Properties (IVT) had the best month in 2021 by a mid-cap US stock in October 2021, returning 2,057.3%.

ASSET	MONTH	% RETURN
Inventrust Properties (IVT)	October 2021	2,057.29%
Inventrust Properties (IVT)	September 2021	1,430.95%
Trump Media & Technology (DJT)	October 2021	577.5%
Applied Blockchain (APLD)	April 2021	417.24%
Globalstar (GSAT)	January 2021	215.41%
Applied Blockchain (APLD)	January 2021	165.87%
Applied Blockchain (APLD)	October 2021	128.78%
Lucid (LCID)	January 2021	128.12%
Riot Blockchain (RIOT)	February 2021	116.86%
WM Technology (MAPSW)	January 2021	107.69%
Hut 8 Corp Common Stock (HUT)	February 2021	107.26%
Terawulf (WULF)	June 2021	106.97%
Xenon Pharmaceuticals (XENE)	October 2021	103.2%
Applied Blockchain (APLD)	February 2021	100%
Nuvalent (NUVL)	August 2021	96.92%
Upstart Holdings (UPST)	March 2021	92.96%
Upstart Holdings (UPST)	August 2021	87.8%
Tecnoglass (TGLS)	May 2021	87.31%
Ligand Pharmaceuticals (LGND)	January 2021	86.17%
Vera Therapeutics (VERA)	November 2021	85.11%
Criteo (CRTO)	February 2021	84.69%
Canoo (GOEVW)	November 2021	81.82%
QXO (QXO)	June 2021	80.83%
Applied Blockchain (APLD)	June 2021	79.83%
PureCycle Technologies (PCTTW)	June 2021	79.71%

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