* S&P 500, Nasdaq hit record highs for second day in a row
* Wayfair revenue beat lifts shares to record highs
* Apple set to close with market cap above $800b
* Dow -0.12 pct, S&P -0.09 pct, Nasdaq +0.25 pct (Updates to afternoon)
By Noel Randewich
May 9 (Reuters) - The S&P 500 slipped marginally on Tuesday after edging up to an intra-day record high for the second straight session, with a rise in Marriott International and other consumer discretionary shares offsetting falling energy shares.
Better-than-expected quarterly earnings from U.S. companies and Emmanuel Macron's victory in the French presidential election on Sunday have given investors confidence, but valuations for U.s. stocks are already higher than average.
The hope that President Donald Trump will cut corporate and personal taxes remained in focus for investors.
Underscoring the lack of new catalysts on Wall Street, the S&P 500 has not moved more than 0.4 percent in either direction in the past 11 trading days.
"Earnings are improving and the potential for tax reform plays a big role. Why would you want to sell stocks here when you might get a tax break later on?" said Bruce Bittles, chief investment strategist for Robert W. Baird & Co.
At 2:38 pm ET, the Dow Jones Industrial Average was down 0.12 percent to 20,986.22 points and the S&P 500 had lost 0.09 percent to 2,397.21.
The Nasdaq Composite added 0.25 percent to 6,117.63 and was on track to close at a record high. It was helped by a 0.5-percent rise in Apple, which was set to close for the first time ever with a market capitalization above $800 billion.
Four of the 11 major S&P sectors were higher, led by consumer discretionary, while the typically defensive plays such as utilities and telecom services fell.
Energy dropped 0.81 percent on the back of falling oil prices.
Shares of Valeant Pharmaceuticals jumped 24 percent after the company posted its first profit in six quarters.
Sturm Ruger & Company jumped 11 percent, leading other gun makers higher after its quarterly report suggested a drop in demand after Trump's election may be bottoming out.
Endo International, Office Depot and Marriott also rose after reporting better-than-expected quarterly earnings.
Wayfair surged 25 percent to an all-time high after the online furniture retailer revenue beat analysts' expectations.
Declining issues outnumbered advancing ones on the NYSE by a 1.27-to-1 ratio; on Nasdaq, a 1.01-to-1 ratio favored advancers.
The S&P 500 posted 42 new 52-week highs and 3 new lows; the Nasdaq Composite recorded 110 new highs and 49 new lows. (Additional reporting by Yashaswini Swamynathan in Bengaluru and Caroline Valetkevitch in New York; Editing by Nick Zieminski)