UnitedHealth (UNH) had the highest return last month by a mega-cap US stock, returning 10.9%.

ASSET	MONTH	% RETURN
UnitedHealth (UNH)	March 2025	10.88%
Exxon Mobil (XOM)	March 2025	6.47%
Novartis AG ADR (NVS)	March 2025	5.28%
Chevron (CVX)	March 2025	4.91%
Philip Morris International (PM)	March 2025	3.43%
Berkshire Hathaway (BRK.B)	March 2025	3.17%
Berkshire Hathaway (BRK.A)	March 2025	2.94%
Coca-Cola (KO)	March 2025	2.72%
McDonald’s (MCD)	March 2025	1.38%
Johnson & Johnson (JNJ)	March 2025	0.53%
AbbVie (ABBV)	March 2025	-0.22%
LIN TV (LIN)	March 2025	-0.41%
T-Mobile US (TMUS)	March 2025	-0.96%
Alibaba (BABA)	March 2025	-1.33%
Merck (MRK)	March 2025	-1.36%
Procter & Gamble (PG)	March 2025	-1.82%
International Business Machines (IBM)	March 2025	-2.39%
Visa Inc Class A (V)	March 2025	-3.45%
AstraZeneca PLC ADR (AZN)	March 2025	-3.6%
Abbott Laboratories (ABT)	March 2025	-4%
Cisco Systems (CSCO)	March 2025	-4.16%
Palantir Technologies Inc Class A Common Stock (PLTR)	March 2025	-4.69%
Mastercard (MA)	March 2025	-5.06%
Netflix (NFLX)	March 2025	-5.13%
Microsoft (MSFT)	March 2025	-5.87%

Mega-cap stocks are treated as having a market cap of $200B+.