American International (AIG) had the lowest return between 2008 and 2009 by a US stock in the S&P 500 (GSPC), returning -97.4%.

ASSET	YEARS	% RETURN
American International (AIG)	2008-2009	-97.39%
MGM Resorts International (MGM)	2008-2009	-89.21%
Citigroup (C)	2008-2009	-88.22%
Las Vegas Sands (LVS)	2008-2009	-85.57%
Caesars Entertainment (CZR)	2008-2009	-80.85%
Valero Energy (VLO)	2008-2009	-76.13%
Regions Financial (RF)	2008-2009	-75.45%
KeyCorp (KEY)	2008-2009	-74.71%
Huntington Bancshares (HBAN)	2008-2009	-73.17%
Textron (TXT)	2008-2009	-71.84%
Hartford Financial Services (HIG)	2008-2009	-70.91%
Axon Enterprise (AXON)	2008-2009	-69.6%
Electronic Arts (EA)	2008-2009	-69.41%
Garmin (GRMN)	2008-2009	-65.28%
Cadence Design Systems (CDNS)	2008-2009	-64.62%
Principal Financial (PFG)	2008-2009	-63.65%
T-Mobile US (TMUS)	2008-2009	-61.09%
United Airlines (UAL)	2008-2009	-60.84%
Jacobs Solutions (J)	2008-2009	-60.66%
Bank of America (BAC)	2008-2009	-60.59%
Nasdaq (NDAQ)	2008-2009	-60.2%
Fifth Third Bancorp (FITB)	2008-2009	-58.81%
Hologic (HOLX)	2008-2009	-57.93%
GE Aerospace (GE)	2008-2009	-54.84%
Assurant (AIZ)	2008-2009	-54.3%