The S&P 500 raced ahead at the outset, despite some disappointing corporate updates and the oil price coming off the top.
Having popped its head above the $49 mark, the price of West Texas intermediate ebbed to $48.93, but was still up around half a percentage point on the day.
Results from the Campbell Soup Company (NYSE:CPX) were not to investors' tastes, resulting in the shares shedding 6%.
Sportswear seller Foot Locker Inc (NYSE:FL) got a kicking as its first quarter numbers also disappointed. The shares fell 6.7%.
Faring slightly less badly was industrial and agricultural machinery maker Deere & Company (NYSE:DE) after its fiscal second quarter update. Despite beating expectations with earnings and revenue, the shares tumbled 4.35 to $78.73.
The negative reactions to results from these blue-chips meant the top-shares index, the S&P 500, made less progress than indices that track smaller stocks.
The S&P 500 was up 0.7%, or 14 points, at 2,054, while the S&P 400, which focuses on medium caps, was up 1.1% (15 points) at 1,446 and the Russell 2,000, a gauge to the performance of small caps, was also up 1.1% (12 points) at 1,107.
InterOil Corporation (USA) (NYSE:IOC) saw its market value rise by a third to $2.1bn as Aussie peer launched a $2.2bn bid.
InterOil shares rose to $42.12 as the board succumbed to an offer worth $40.25 for each InterOil share.
Preview
Helped by a rise in the oil price, US blue-chips are expected to open firmer.
The price of West Texas intermediate, the US crude benchmark, pushed past $49 a barrel overnight and is heading for $50.
With energy companies like to be in demand, the S&P 500 is expected to open more than seven points up from last night's close of 2,040.
The Dow Jones average is tipped to kick off some 55 points higher at around 17,490.
On the results front, the Campbell Soup Company (NYSE:CPX) was in hot water, shedding 4.3% in pre-market trading, after its sales figures came in below expectations.
First quarter numbers from sportswear seller Foot Locker Inc (NYSE:FL) also disappointed. The shares were off 4% in screen-based trading.