ResMed (RMD) had the lowest return in April 2007 by a US stock in the S&P 500 (GSPC), returning -15.8%.

ASSET	MONTH	% RETURN
ResMed (RMD)	April 2007	-15.82%
United Airlines (UAL)	April 2007	-12.79%
Akamai Technologies (AKAM)	April 2007	-12.09%
Delta Air Lines (DAL)	April 2007	-10.11%
Live Nation Entertainment (LYV)	April 2007	-8.02%
Bunge (BG)	April 2007	-7.95%
Fair Isaac (FICO)	April 2007	-7.92%
Marriott International (MAR)	April 2007	-7.38%
PTC (PTC)	April 2007	-6.72%
Tyler Technologies (TYL)	April 2007	-6.27%
CoreSite Realty (COR)	April 2007	-5.87%
Henry Schein (HSIC)	April 2007	-5.73%
Micron Technology (MU)	April 2007	-5.44%
Lennox International (LII)	April 2007	-5.13%
Take-Two Interactive Software (TTWO)	April 2007	-4.96%
Brown & Brown (BRO)	April 2007	-4.95%
Netflix (NFLX)	April 2007	-4.85%
KeyCorp (KEY)	April 2007	-4.75%
Seagate Technology (STX)	April 2007	-4.73%
Best Buy (BBY)	April 2007	-4.42%
BlackRock (BLK)	April 2007	-4.14%
Cardinal Health (CAH)	April 2007	-4.11%
MGM Resorts International (MGM)	April 2007	-4.07%
STERIS (STE)	April 2007	-4.05%
Walgreens Boots Alliance (WBA)	April 2007	-4.02%