The S&P 500 added 29.63 points, or 2.3 percent, to close on the session high of 1315.13.
The Nasdaq 100 added 58.82 points, or 2.36 points, to close at 2546.32. It was the index's largest gain for a single session in 2012.
The Russell 2000 outperformed its large-cap peers by nearly a quarter of a percent. The RUT closed higher by 19.08 points, or 2.56 percent, to close at 765.17.
S&P 500
Resistance is now 1316, followed by 1317.50, 1320.15, and 1323-30.Nasdaq 100
Support is 1315.19, followed by 1310.01, 1307.98, 1305, 1294.98, 1290-1285.
Resistance is now 2547, followed by 2550, 2555, 2558.14, 2565, and 2570.70 (last Tuesday's high).Russell 2000
Support is now 2537.44, followed by 2533.50, 2530, 2527.03, and 2512.44-2500.
Resistance is now 766, followed by 770.49, 772.89, and 780.
Support is now 764.54, followed by 763.39, 763, 762.22, and 760.
