American International (AIG) had the lowest return between 2007 and 2009 by a large-cap US stock, returning -97.8%.

ASSET	YEARS	% RETURN
American International (AIG)	2007-2009	-97.85%
Natwest (NWG)	2007-2009	-94.83%
Citigroup (C)	2007-2009	-93.42%
Cheniere Energy (LNG)	2007-2009	-91.74%
American Airlines (AAL)	2007-2009	-91.02%
Lloyds Banking Group PLC ADR (LYG)	2007-2009	-85.68%
MGM Resorts International (MGM)	2007-2009	-84.11%
Regions Financial (RF)	2007-2009	-83.79%
Las Vegas Sands (LVS)	2007-2009	-83.67%
KeyCorp (KEY)	2007-2009	-83.53%
Huntington Bancshares (HBAN)	2007-2009	-82.32%
Celsius (CELH)	2007-2009	-78.92%
Lennar (LEN.B)	2007-2009	-77.9%
Builders FirstSource (BLDR)	2007-2009	-76.7%
ING Group NV ADR (ING)	2007-2009	-75.81%
UBS (UBS)	2007-2009	-74.34%
Neurocrine Biosciences (NBIX)	2007-2009	-73.9%
Fifth Third Bancorp (FITB)	2007-2009	-73.69%
Lennar (LEN)	2007-2009	-73.43%
Mizuho Financial (MFG)	2007-2009	-73.43%
Webster Financial (WBS)	2007-2009	-73%
Altria (MO)	2007-2009	-72.82%
Orix Corp Ads (IX)	2007-2009	-72.71%
Hartford Financial Services (HIG)	2007-2009	-72.24%
Sumitomo Mitsui Financial (SMFG)	2007-2009	-70.14%

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