The S&P 500 index closed on Friday at its highest level since before the collapse of Lehman Brothers in 2008.
The index closed at 1365, up 8.6% for the year.
The Dow Jones industrial average was down 11.17 points, or 0.09%, at 12,973.52. The Nasdaq Composite Index was up 6.27 points, or 0.21%, at 2,963.25.
Brent crude oil rose $US1.85 to settle at $125.47 per barrel, its fifth consecutive day of gains.
The European Union has banned imports of oil from 1 July over fears it is developing nuclear weapons.