BioNTech SE (BNTX) had the lowest return in April 2020 by a large-cap US stock, returning -15.7%.

ASSET	MONTH	% RETURN
BioNTech SE (BNTX)	April 2020	-15.74%
Howmet Aerospace (HWM)	April 2020	-15.13%
Pearson PLC ADR (PSO)	April 2020	-12.54%
Arch Capital (ACGL)	April 2020	-11.88%
GE Aerospace (GE)	April 2020	-9.57%
Shell PLC ADR (SHEL)	April 2020	-9.43%
Cincinnati Financial (CINF)	April 2020	-8.53%
TotalEnergies SE ADR (TTE)	April 2020	-8.34%
Southwest Airlines (LUV)	April 2020	-8.22%
Eni SpA ADR (E)	April 2020	-8.03%
Zoom Video Communications (ZM)	April 2020	-6.46%
Telefonica Brasil SA ADR (VIV)	April 2020	-6.03%
BP PLC ADR (BP)	April 2020	-5.67%
Banco Santander SA ADR (SAN)	April 2020	-5.66%
YPF Sociedad Anonima (YPF)	April 2020	-5.42%
HP (HPQ)	April 2020	-4.55%
Ambev SA ADR (ABEV)	April 2020	-4.44%
Comfort Systems USA (FIX)	April 2020	-4.12%
Biogen (BIIB)	April 2020	-3.88%
Graco (GGG)	April 2020	-3.63%
Everest (EG)	April 2020	-3.56%
Interactive Brokers (IBKR)	April 2020	-3.42%
Service Corporation International (SCI)	April 2020	-3.34%
Delta Air Lines (DAL)	April 2020	-2.56%
Markel (MKL)	April 2020	-1.99%

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