* Dow held above 17,000 on Monday despite decline
* Alcoa to report after market close, revenue seen down
* Groupon rallies in premarket after analyst upgrade
* Futures down: Dow 26 pts, S&P 3.75 pts, Nasdaq 4.75 pts (Updates prices, adds comments from Wal-Mart executive)
By Ryan Vlastelica
NEW YORK, July 8 (Reuters) - U.S. stock index futures pointed to a lower open on Tuesday, suggesting a second day of weakness as investors continued to hold off from making big bets going into the start of corporate earnings season.
* Alcoa Inc, among the first high-profile names to report, will release its results after the market closes on Tuesday. The aluminum maker is seen posting profit growth of more than 50 percent, according to Thomson Reuters data, along with a 3.6 percent decline in revenue. The stock rose 6 cents to $14.80 in premarket trading.
* Recent U.S. economic data has been strong, following a dismal start to the year, and market participants are looking to corporate earnings for confirmation that the economy snapped back in the second quarter. Many analysts are especially looking for an acceleration in revenue growth.
* Bill Simon, the chief executive officer of Wal-Mart's U.S. division, told Reuters that while the domestic job market was improving, that wasn't giving consumers enough confidence to boost their spending.
* Profits for S&P 500 companies are seen growing 6.2 percent in the second quarter, according to Thomson Reuters data, down from the 8.4 percent growth forecast at the start of April. Revenue is seen up 3 percent.
* Market action may be slight until traders get a strong sense of how the earnings season is shaping up. Wells Fargo & Co is among the few S&P 500 companies slated to report this week, but next week will see dozens of bellwether names report, including numerous Dow components.
* S&P 500 e-mini futures fell 3.75 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average e-mini futures fell 26 points and Nasdaq 100 e-mini futures lost 4.75 points.
* Wall Street had its biggest one-day drop in two weeks on Monday, falling on light volume as investors took profits ahead of the start of earnings. Still, the market's uptrend is viewed as intact, and the Dow held above the psychologically important 17,000 level.
* NeuroMetrix Inc shares jumped 30 percent to $2.45 before the bell after the U.S. Food and Drug Administration cleared the company's wearable technology for over-the-counter use in the treatment of chronic pain.
* Groupon Inc was among the most active premarket movers, rising 5.7 percent to $6.82 after B. Riley upgraded the stock to "buy" from "neutral."
* PetSmart Inc will be in focus a day after Longview Asset Management LLC became the latest shareholder calling for the board to consider selling the company, even as the retailer said it was reviewing potential changes in its capital structure. (Editing by Chizu Nomiyama and Nick Zieminski)