Repro Med Systems (KRMD) had the highest return in June 1988 by a US stock, returning 96.5%.

ASSET	MONTH	% RETURN
Repro Med Systems (KRMD)	June 1988	96.49%
Polaris Industries (PII)	June 1988	69.13%
CECO Environmental (CECO)	June 1988	64.3%
Comtech Telecommunications (CMTL)	June 1988	50%
3D Systems (DDD)	June 1988	48.3%
Healthcare Services (HCSG)	June 1988	37.94%
Entergy (ETR)	June 1988	37.5%
RCM Technologies (RCMT)	June 1988	37.47%
ONEOK (OKE)	June 1988	36.85%
BK Technologies (BKTI)	June 1988	36.84%
Powell Industries (POWL)	June 1988	35.29%
Mosaic (MOS)	June 1988	34.38%
Synalloy (ACNT)	June 1988	30.23%
Danaher (DHR)	June 1988	30.09%
Semtech (SMTC)	June 1988	29.03%
Glacier Bancorp (GBCI)	June 1988	27.58%
Bath & Body Works (BBWI)	June 1988	27.57%
Franklin Wireless (FKWL)	June 1988	27.56%
Array Digital Infrastructure (AD)	June 1988	27.2%
Leonardo DRS, Inc Common Stock (DRS)	June 1988	26.32%
Valmont Industries (VMI)	June 1988	26.23%
Allegheny Technologies (ATI)	June 1988	26.21%
Utah Medical Products (UTMD)	June 1988	25.9%
Pure Cycle (PCYO)	June 1988	25%
Lsb Industries (LXU)	June 1988	25%