Insulet (PODD) had the lowest return in January 2015 by a large-cap US stock, returning -36.2%.

ASSET	MONTH	% RETURN
Insulet (PODD)	January 2015	-36.22%
Deckers Outdoor (DECK)	January 2015	-27.99%
Freeport-McMoran Copper & Gold (FCX)	January 2015	-27.02%
Alamos Gold (AGI)	January 2015	-24.07%
Molson Coors Beverage (TAP.A)	January 2015	-23.21%
Carpenter Technology (CRS)	January 2015	-23.04%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	January 2015	-21.99%
Ally Financial (ALLY)	January 2015	-21.25%
Centrais Elétricas Brasileiras SA - Eletrobrás (EBR.B)	January 2015	-20.42%
United Rentals (URI)	January 2015	-19.65%
TechnipFMC (FTI)	January 2015	-19.29%
Banco Santander SA ADR (SAN)	January 2015	-19.03%
Canadian Imperial Bank Of Commerce (CM)	January 2015	-18.81%
MasTec (MTZ)	January 2015	-18.49%
Regions Financial (RF)	January 2015	-18.31%
Allegheny Technologies (ATI)	January 2015	-18.13%
Huazhu (HTHT)	January 2015	-18.11%
Bank of Montreal (BMO)	January 2015	-17.79%
Discover Financial Services (DFS)	January 2015	-17.52%
Targa Resources (TRGP)	January 2015	-17.16%
Tenet Healthcare (THC)	January 2015	-17.08%
Royal Bank of Canada (RY)	January 2015	-16.98%
Aecom Technology (ACM)	January 2015	-16.96%
Micron Technology (MU)	January 2015	-16.96%
Prudential Financial (PRU)	January 2015	-16.62%

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