Stocks were set to open lower on Wednesday after two days of strong gains, as investors await the unofficial beginning of the earnings season.

Alcoa Inc , the first Dow component to report its quarterly scorecard this session, will be scrutinized as investors look for stronger evidence to support a rise in stocks after the recent spike.

We've had a two-day run-up, a breathtaking move to the upside after a recent two-week pause, said Peter Kenny, managing director at Knight Equity Markets in Jersey City, New Jersey.

Earnings season is now upon us, and no one is willing to make a bet after the two-day run-up without seeing the numbers. Today should be a day of less drama as the market gets ready to digest the results.

One day ahead of most retail same-store sales reports for September, Costco Wholesale Corp posted a quarterly profit that beat expectations, suggesting an improvement in the weak U.S. retail environment.

S&P 500 futures fell 1.6 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 futures lost 7 points and Nasdaq 100 futures shed 3.75 points. Inc stock will be in view as the online retailer introduces Kindle, its wireless electronic reader, in over 100 countries, including China and most of Europe, and will lower its price in the United States.

French media giant Vivendi SA is likely to sell its 20 percent stake in media company NBC Universal and may discuss the matter at a board meeting on October 14, a source close to the situation told Reuters on Wednesday.

U.S. stocks rose on Tuesday amid signs the global economy was recovering and optimism that corporate earnings reports will beat expectations.

(Additional reporting by Ryan Vlastelica; editing by Jeffrey Benkoe)