Redwire (RDW) had the highest return in May 2026 by a mid-cap US stock, returning 164.5%.

ASSET	MONTH	% RETURN
Redwire (RDW)	May 2026	164.48%
Enphase Energy (ENPH)	May 2026	105.66%
Sellas Life Sciences (SLS)	May 2026	88.08%
Penguin Solutions (PENG)	May 2026	86.91%
Voyager Technologies (VOYG)	May 2026	83.85%
Xometry (XMTR)	May 2026	83.07%
Vishay Intertechnology (VSH)	May 2026	82.18%
Himax Technologies (HIMX)	May 2026	77.02%
Intuitive Machines (LUNR)	May 2026	72.42%
Ouster, Inc Common Stock (OUST)	May 2026	70.68%
Acm Research (ACMR)	May 2026	68.47%
Hyperliquid Strategies Inc Common Stock (PURR)	May 2026	65.12%
BlackBerry (BB)	May 2026	63.34%
Hut 8 Corp Common Stock (HUT)	May 2026	62.12%
Navitas Semiconductor (NVTS)	May 2026	61.7%
Bruker (BRKR)	May 2026	59.68%
Liquidia Technologies (LQDA)	May 2026	57.77%
Global Business Travel (GBTG)	May 2026	57.24%
Fluence Energy (FLNC)	May 2026	56.16%
Bitdeer Technologies Group Class A Ordinary Shares (BTDR)	May 2026	52.22%
AAON (AAON)	May 2026	50.19%
D-Wave Quantum Inc Common Stock (QBTS)	May 2026	49.95%
ChronoScale (CHRN)	May 2026	49.76%
Rigetti Computing (RGTI)	May 2026	48.83%
Abcellera Biologics (ABCL)	May 2026	48.67%

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