Exelixis (EXEL) had the worst month in 2014 by a large-cap US stock in March 2014, returning -49%.

ASSET	MONTH	% RETURN
Exelixis (EXEL)	March 2014	-48.99%
TKO (TKO)	May 2014	-43.43%
Best Buy (BBY)	January 2014	-40.78%
Freedom (FRHC)	October 2014	-38.46%
Kinross Gold (KGC)	October 2014	-35.24%
YPF Sociedad Anonima (YPF)	January 2014	-32.72%
TKO (TKO)	April 2014	-32.48%
AngloGold Ashanti (AU)	October 2014	-30.97%
Centrais Electricas Brasileiras (EBR)	September 2014	-29.32%
Petróleo Brasileiro SA - Petrobras (PBR.A)	September 2014	-29.06%
GameStop (GME)	January 2014	-28.65%
AngloGold Ashanti (AU)	September 2014	-28.57%
Petroleo Brasileiro Petrobras SA ADR (PBR)	September 2014	-28.33%
Veeva Systems Inc Class A (VEEV)	April 2014	-28.05%
Insmed (INSM)	April 2014	-26.82%
Viper Energy Ut (VNOM)	September 2014	-26.32%
Alnylam Pharmaceuticals (ALNY)	April 2014	-25.85%
Alamos Gold (AGI)	January 2014	-25.69%
Intuitive Surgical (ISRG)	April 2014	-25.58%
Centrais Elétricas Brasileiras SA - Eletrobrás (EBR.B)	September 2014	-25.31%
Freedom (FRHC)	July 2014	-25%
Ecopetrol SA ADR (EC)	November 2014	-24.46%
Halliburton (HAL)	November 2014	-23.96%
Veeva Systems Inc Class A (VEEV)	March 2014	-23.63%
Guidewire Software (GWRE)	April 2014	-23.03%

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