VinFast Auto Ltd Ordinary Shares (VFS) had the lowest return in September 2023 by a mid-cap US stock, returning -61.6%.

ASSET	MONTH	% RETURN
VinFast Auto Ltd Ordinary Shares (VFS)	September 2023	-61.56%
Eos Energy Enterprises (EOSE)	September 2023	-55.11%
PTC Therapeutics (PTCT)	September 2023	-43.49%
Sezzle (SEZL)	September 2023	-40.01%
Terawulf (WULF)	September 2023	-39.71%
Rumble (RUM)	September 2023	-39.21%
Arcutis Biotherapeutics (ARQT)	September 2023	-38.33%
Ondas (ONDS)	September 2023	-37.95%
Travere Therapeutics (TVTX)	September 2023	-37.87%
American Bitcoin (ABTC)	September 2023	-36.23%
Opendoor Technologies (OPEN)	September 2023	-34.33%
ViaSat (VSAT)	September 2023	-33.74%
ODDITY Tech Ltd Class A Ordinary Shares (ODD)	September 2023	-32.23%
CAVA (CAVA)	September 2023	-31.86%
United Natural Foods (UNFI)	September 2023	-30.14%
RH (RH)	September 2023	-28.84%
Bitdeer Technologies Group Class A Ordinary Shares (BTDR)	September 2023	-28.8%
Archer Aviation (ACHR)	September 2023	-28.02%
Kymera Therapeutics (KYMR)	September 2023	-27.57%
Cipher Mining (CIFR)	September 2023	-27.19%
Grupo Financiero Galicia SA ADR (GGAL)	September 2023	-26.94%
Mineralys Therapeutics, Inc Common Stock (MLYS)	September 2023	-26.9%
BBVA Banco Frances SA ADR (BBAR)	September 2023	-26.38%
Aurora Innovation (AUR)	September 2023	-26.33%
Chefs Warehouse (CHEF)	September 2023	-26.18%

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