* Futures up: Dow 33 pts, S&P 4.5 pts, Nasdaq 2.5 pts
July 25 (Reuters) - S&P and Dow futures were higher on Tuesday, with the earnings season gaining momentum and ahead of a two-day Federal Reserve meeting, while a fall in Google-parent Alphabet weighed on Nasdaq futures.
* Shares of Alphabet were down 2.5 percent in premarket trading, after the tech giant noted that costs were rising faster than sales and warned that expenses would remain high as more searches shift to mobile devices.
* The S&P tech index has been the best performing sector this year and earnings from big tech companies will be closely watched to see if the sector can continue its run.
* Amazon and Facebook report results later this week, while Apple is due to report next week.
* The market's run to record highs has left equities relatively expensive and investors are counting on earnings to justify the valuations.
* The S&P 500 is trading at around 18 times earnings estimates for the next 12 months, well above their long-term average of 15 times.
* Earnings are expected to have climbed 8.8 percent in the second quarter, compared with an 8 percent rise estimated at the start of the month, according to Thomson Reuters I/B/E/S.
* This week alone, 190 S&P 500 companies are expected to report quarterly results.
* Advanced Micro Devices, AT&T, Chipotle and Chubb are among the major companies that will report after the closing bell.
* The Fed starts a two-day meeting later in the day to discuss its monetary stance and the timing of its long-awaited balance sheet reduction, a plan most likely to be detailed in September.
* While no rate hike is expected due to subdued inflation, the central bank's statement on Wednesday will be parsed for clues on the pace of future rate hikes.
* Economic data at 10 a.m. ET (1400 GMT) is expected to show consumer confidence index slipped to 116.5 in July from 118.9 in June.
* Biogen rose 3.9 percent after the biotech company reported quarterly results that beat expectations and raised its full-year revenue forecast.
* Michael Kors was up 3.1 percent after the retailer agreed to buy luxury shoemaker Jimmy Choo for $1.2 billion.
* Centene was up 1 percent after the health insurer's quarterly profit beat estimates.
Futures snapshot at 6:42 a.m. ET:
* Dow e-minis were up 33 points, or 0.15 percent, with 10,204 contracts changing hands.
* S&P 500 e-minis were up 4.5 points, or 0.18 percent, with 77,476 contracts traded.
* Nasdaq 100 e-minis were up 2.5 points, or 0.04 percent, on volume of 14,983 contracts. (Reporting by Tanya Agrawal in Bengaluru; Editing by Anil D'Silva)