First Majestic Silver (AG) had the highest return in March 2011 by a large-cap US stock, returning 34.4%.

ASSET	MONTH	% RETURN
First Majestic Silver (AG)	March 2011	34.43%
EXACT Sciences (EXAS)	March 2011	29.91%
Sterling Construction (STRL)	March 2011	28.27%
Harmony Gold Mining (HMY)	March 2011	27.2%
Leonardo DRS, Inc Common Stock (DRS)	March 2011	26.18%
Insmed (INSM)	March 2011	25%
Regeneron Pharmaceuticals (REGN)	March 2011	23.36%
MercadoLibre (MELI)	March 2011	21.96%
Western Digital (WDC)	March 2011	21.7%
AeroVironment (AVAV)	March 2011	20.54%
Westinghouse Air Brake Technologies (WAB)	March 2011	19.15%
Builders FirstSource (BLDR)	March 2011	17.84%
Westlake Chemical (WLK)	March 2011	17.5%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	March 2011	16.85%
Ulta Beauty (ULTA)	March 2011	16.26%
Insulet (PODD)	March 2011	16.23%
Huntington Ingalls Industries (HII)	March 2011	16.18%
Motorola Solutions (MSI)	March 2011	15.54%
Coca-Cola Consolidated (COKE)	March 2011	15.4%
Tesla (TSLA)	March 2011	15.39%
Incyte (INCY)	March 2011	15.36%
Netflix (NFLX)	March 2011	15.32%
Baidu (BIDU)	March 2011	15.11%
Woodside Energy (WDS)	March 2011	15.01%
Tractor Supply (TSCO)	March 2011	14.87%

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