Waste Management (WM) had the lowest return in July 1999 by a large-cap US stock, returning -52.3%.

ASSET	MONTH	% RETURN
Waste Management (WM)	July 1999	-52.34%
Jones Lang LaSalle (JLL)	July 1999	-52.19%
eBay (EBAY)	July 1999	-36.23%
Booking (BKNG)	July 1999	-35.35%
Tractor Supply (TSCO)	July 1999	-30.04%
STERIS (STE)	July 1999	-29.74%
Quanta Services (PWR)	July 1999	-26.48%
TIM Participacoes (TIMB)	July 1999	-25.07%
Western Digital (WDC)	July 1999	-25%
Telefonica Brasil SA ADR (VIV)	July 1999	-24.87%
Telkom Indonesia (Persero) Tbk PT ADR Rep 100 B (TLK)	July 1999	-23.23%
Yum! Brands (YUM)	July 1999	-22.87%
L3Harris Technologies (LHX)	July 1999	-22.65%
Neurocrine Biosciences (NBIX)	July 1999	-22.35%
Albemarle (ALB)	July 1999	-22.01%
Pegasystems (PEGA)	July 1999	-20.24%
Amazon (AMZN)	July 1999	-20.11%
Biomarin Pharmaceutical (BMRN)	July 1999	-20%
Cadence Design Systems (CDNS)	July 1999	-18.75%
Flex (FLEX)	July 1999	-18.59%
Lennar (LEN)	July 1999	-18.49%
Charles Schwab (SCHW)	July 1999	-18.02%
FedEx (FDX)	July 1999	-17.89%
Chubb (CB)	July 1999	-17.88%
Encompass Health (EHC)	July 1999	-17.65%

Large-cap stocks are treated as having a market cap of $10B+.