* Futures: Dow 100 pts, S&P 5.25 pts, Nasdaq 20 pts
By Tanya Agrawal
Aug 1 (Reuters) - U.S. stock index futures started the month on a strong note, with Dow futures surging 100 points on Tuesday, driven by a set of upbeat earnings reports and ahead of Apple's quarterly results.
* Shares of Dow-component Apple were up 0.36 percent in premarket trading. The company is due to report results after the closing bell.
* The Dow industrials hit a record closing high on Monday, helped by Boeing, while selling in technology companies kept the S&P 500 in check and pulled the Nasdaq lower.
* Tech stocks have been volatile in the past few months, following a record-setting rally that has made the sector the best performer this year.
* Investors have been counting on earnings to support high valuations for equities. The S&P 500 is trading at about 18 times earnings estimates for the next 12 months, above its long-term average of 15 times.
* S&P 500 earnings are expected on average to have grown 10.8 percent in the second quarter, according to Thomson Reuters I/B/E/S.
* Economic data expected later in the day includes core PCE numbers - the Federal Reserve's preferred metric to gauge inflation - for June that is expected to have edged up 0.1 percent from a similar increase in May.
* Softening inflation and incessant political turmoil has hit prospects of another rate hike this year. Traders are pricing in a 47 percent chance of a December hike, compared with a 50 percent probability a month ago, according to CME's Fedwatch tool.
* Construction spending numbers and manufacturing activity for June are also expected.
* Oil traded near $53 a barrel, close to a two-month high, supported by signs that a persistent inventory glut is starting to ease and strong global demand, although stronger OPEC production kept a lid on gains.
* Pfizer was up 0.63 percent after the drugmaker's quarterly revenue fell slightly but it increased the mid-point of its profit guidance.
* Factory automation equipment maker Emerson Electric fell 2 percent after the company's quarterly profit fell.
* Under Armour edged down 0.61 percent after the sportswear maker cut its revenue forecast.
Futures snapshot at 7:08 a.m. ET (1108 GMT):
* Dow e-minis were up 100 points, or 0.46 percent, with 28,695 contracts changing hands.
* S&P 500 e-minis were up 5.25 points, or 0.21 percent, with 147,627 contracts traded.
* Nasdaq 100 e-minis were up 20 points, or 0.34 percent, on volume of 24,865 contracts. (Reporting by Tanya Agrawal in Bengaluru; Editing by Anil D'Silva)