There was no pattern among leading retailers early in the trading session, with Best Buy and Macy's higher and Williams-Sonoma and Target lower.
Analysts expect good overall holiday sales due to the solid US economy, but predict some retailers will struggle to keep profit margins robust due to heavy discounting and the influence of online options.
About 20 minutes into trading, the Dow Jones Industrial Average was at 23,394.81, up 0.2 percent.
The broad-based S&P 500 rose 0.1 percent to 2,580.25, while the tech-rich Nasdaq Composite Index gained 0.2 percent to 6,793.69.
Analysts were expecting lower-than-usual trading volumes due to the Thanksgiving holiday, which will shut markets on Thursday and result in a half-day of trading on Friday.
In merger news, chip-maker jumped 7.8 percent after it agreed to be acquired by Marvell Technology Group for about $6 billion. The deal will lift Marvell's total potential market to more than $12 billion.