TKO (TKO) had the lowest return in April 2014 by a large-cap US stock, returning -32.5%.

ASSET	MONTH	% RETURN
TKO (TKO)	April 2014	-32.48%
Veeva Systems Inc Class A (VEEV)	April 2014	-28.05%
Insmed (INSM)	April 2014	-26.82%
Alnylam Pharmaceuticals (ALNY)	April 2014	-25.85%
Intuitive Surgical (ISRG)	April 2014	-25.58%
Guidewire Software (GWRE)	April 2014	-23.03%
MakeMyTrip (MMYT)	April 2014	-22.16%
Paylocity Holdng (PCTY)	April 2014	-21.47%
DexCom (DXCM)	April 2014	-21.24%
Insulet (PODD)	April 2014	-20.49%
Workday (WDAY)	April 2014	-20.19%
ICON (ICLR)	April 2014	-18.79%
ServiceNow (NOW)	April 2014	-17.23%
Ubiquiti Networks (UI)	April 2014	-15.4%
Biomarin Pharmaceutical (BMRN)	April 2014	-15.03%
Apollo Global Management LLC Class A (APO)	April 2014	-14.42%
CoStar (CSGP)	April 2014	-14.19%
Suzano Papel e Celulose SA ADR (SUZ)	April 2014	-13.99%
Builders FirstSource (BLDR)	April 2014	-13.93%
Paycom Soft (PAYC)	April 2014	-13.91%
Ciena (CIEN)	April 2014	-13.55%
Ally Financial (ALLY)	April 2014	-13.45%
Neurocrine Biosciences (NBIX)	April 2014	-13.24%
Lululemon Athletica (LULU)	April 2014	-12.8%
VeriSign (VRSN)	April 2014	-12.76%

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