Teck Resources Ltd Class B (TECK) had the lowest return between 2014 and 2015 by a large-cap US stock, returning -83.9%.

ASSET	YEARS	% RETURN
Teck Resources Ltd Class B (TECK)	2014-2015	-83.94%
Freeport-McMoran Copper & Gold (FCX)	2014-2015	-80.81%
Ecopetrol SA ADR (EC)	2014-2015	-78.76%
Coeur Mining (CDE)	2014-2015	-77.62%
Vale SA ADR (VALE)	2014-2015	-75.79%
ArcelorMittal SA ADR (MT)	2014-2015	-75.46%
Leonardo DRS, Inc Common Stock (DRS)	2014-2015	-75%
Petróleo Brasileiro SA - Petrobras (PBR.A)	2014-2015	-74.57%
Alamos Gold (AGI)	2014-2015	-72.56%
Ovintiv (OVV)	2014-2015	-70.41%
Targa Resources (TRGP)	2014-2015	-67.14%
Petroleo Brasileiro Petrobras SA ADR (PBR)	2014-2015	-66.87%
Allegheny Technologies (ATI)	2014-2015	-66.75%
TIM Participacoes (TIMB)	2014-2015	-65.41%
Antero Resources (AR)	2014-2015	-64.98%
Harmony Gold Mining (HMY)	2014-2015	-64.13%
Nebius (NBIS)	2014-2015	-63.7%
Wynn Resorts (WYNN)	2014-2015	-62.22%
Kinross Gold (KGC)	2014-2015	-59.1%
NRG Energy (NRG)	2014-2015	-57.06%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	2014-2015	-55.69%
BHP (BHP)	2014-2015	-55.56%
Kinder Morgan (KMI)	2014-2015	-54.12%
Contura Energy (CTRA)	2014-2015	-53.89%
Viper Energy Ut (VNOM)	2014-2015	-52.7%

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