* Trump cancels US envoys' visit to Pakistan

* Verizon rises after reporting better-than-expected

subscriber adds

* Domino's slides after missing Q1 sales estimates

(Updates to market close)

By Stephen Culp and Niket Nishant

NEW YORK, April 27 (Reuters) - The S&P 500 and the

Nasdaq eked out modest gains on Monday in muted trading, as

investors took a breath at the top of an eventful week, with

earnings, economic data, the U.S. Federal Reserve's rate

decision and the ebb and flow of Middle East tensions all

crowding the docket.

All three major U.S. stock indexes wavered throughout the

session, showing little conviction in either direction after

last week's rally sent the S&P 500 and the Nasdaq to a series of

record closing highs.

The session began with the S&P 500 up over 100% since the

bull market began in October 2022.

"The market is just trying to deal with the rally that's

been going on and digest the latest all-time highs that we've

made on the indices," said Robert Pavlik, senior portfolio

manager at Dakota Wealth in Fairfield, Connecticut. "And it's

trying to figure out whether or not those all-time highs are

justified."

First-quarter earnings season has hit full stride, with a

host of high-profile firms slated to report this week, including

five of the Magnificent Seven technology megacaps, Amazon ( AMZN )

, Alphabet, Meta Platforms ( META ), Apple ( AAPL )

and Microsoft ( MSFT ). Investors will assess the

extent to which these companies are beginning to reap benefits

of massive expenditures on artificial intelligence.

As of Friday, 139 companies in the S&P 500 have posted

first-quarter results. Of those, 81% have beaten estimates.

Analysts now see aggregate S&P 500 earnings growth of 16.1%

year-on-year, up from 14.4% on April 1, according to LSEG

I/B/E/S.

The companies due to report this week account for roughly

44% of the S&P 500's market capitalization, according to Raymond

James.

"Guidance has been pretty good. We're seeing earnings growth

of 15%, and I would classify that as a very good environment,

except the road has gotten a lot more bumpy," Pavlik added,

referring to geopolitical tensions in the Middle East.

Attempts to revive peace talks between the U.S. and Iran

continue following President Donald Trump's decision to call off

negotiators' trip to Islamabad for another round of face-to-face

talks. Iran continues to restrict shipments through the Strait

of Hormuz, with Iranian officials demanding that Washington lift

its blockade as a precondition to further negotiation.

On Tuesday, the Federal Reserve is scheduled to convene for

its two-day policy meeting, widely expected to culminate in the

decision to leave interest rates unchanged. The accompanying

statement and Fed Chair Jerome Powell's press conference will be

scrutinized for clues regarding the central bank's assessment of

U.S. economic health and the inflationary impact of spiking

energy prices resulting from the U.S.-Israeli war on Iran.

According to preliminary data, the S&P 500

gained 8.93 points, or 0.12%, to end at 7,174.01 points,

while the Nasdaq Composite gained 49.78 points, or

0.20%, to 24,886.38. The Dow Jones Industrial Average

fell 57.82 points, or 0.12%, to 49,172.89.

Verizon advanced following the telecom company's

annual forecast hike due to stronger-than-expected subscriber

adds.

Domino's Pizza slid after the pizza chain missed

first-quarter sales estimates.

Nvidia ( NVDA ) extended the prior session's 4.3% surge. The

company has reclaimed a market valuation of more than $5

trillion.