Valero (VLO 28.99, +2.09) is up almost 8% at the moment. That makes it the best performer in the S&P 500. Its surge comes as refiners benefit from a drop in oil prices.
Caterpillar (CAT 103.96, +2.99) is the top percentage performer in the Dow as it sports a 3% gain, but Global Defense Technology (GTEC 24.15, +8.07) is up 50% following news that it will be acquired by Ares Management for $24.25 per share in cash.