US STOCKS-S&P 500, Nasdaq futures fall ahead of data storm, megacap earnings

By Lisa Pauline Mattackal and Purvi Agarwal

April 30 (Reuters) - U.S. stock index futures were flat to slightly lower on Wednesday as investors braced for a spate of economic data and corporate results to close a turbulent month for financial markets.

First-quarter gross domestic product data, March's reading of the PCE price index - the Federal Reserve's preferred inflation metric - and ADP employment figures are all due on the day.

The U.S. economy is expected to have stalled or even contracted in the first quarter, with economists sharply downgrading estimates after data on Tuesday showed the goods trade deficit surged to an all-time high in March.

A series of data releases over the month has indicated an increasingly murky economic outlook and a sharp decline in business and consumer sentiment, underscoring the fallout from the rapidly changing U.S. tariff policy.

"The impact of tariffs is unlikely to be felt before the first week of May but we do see a marked slowdown relative to early-in-the-year expectations," said economists at Jefferies.

"From a market perspective, this suggests that the risk sentiment rally is likely to stall and potentially take a step back."

Caterpillar CAT.N was up 2% in premarket trading after its quarterly results, helping futures linked to the Dow.

"Magnificent Seven" members Meta Platforms META.O and Microsoft's MSFT.O were down marginally as investors await their results, due after markets close, for clarity on the outlook for the tech sector and AI-focused investments.

Fanning concerns about a pullback in investments into AI, Super Micro Computer SMCI.O cut its third-quarter forecasts due to delays in customer spending, sending its shares down 16.3%.

Snapchat parent Snap SNAP.N dropped about 14% after saying it would not provide a second-quarter financial forecast. Several companies have cut or even withdrawn guidance due to tariff uncertainty over the past weeks.

At 06:55 a.m. ET, Dow E-minis YMcv1 were up 47 points, or 0.12%, S&P 500 E-minis EScv1 were down 13.5 points, or 0.24%, and Nasdaq 100 E-minis NQcv1 were down 84.75 points, or 0.43%.

The indexes have recouped some ground this month after a sharp slump following the April 2 "Liberation Day" tariff announcements. The Nasdaq is set for gains this month, while the other two are set to slip.

The S&P 500 notched its best winning streak since November on Tuesday, but intraday trading has been choppy over the past few sessions as investors assess rapid trade developments. President Donald Trump signed a pair of orders to soften the blow of auto tariffs on Tuesday.

Wednesday also marks 100 days since Trump took office. Erratic changes in trade policies and uncertainty have roiled markets over that period, offsetting initial optimism over the administration's business-friendly policies.

The benchmark S&P 500 .SPX has lost more than 7% since Trump's presidency began, and is off over 9% from its February record close.

Among other stocks, Humana HUM.N gained 5.6% after beating Wall Street estimates for first-quarter profit, while Norwegian Cruise Line Holdings NCLH.N tumbled 7.4% after missing first-quarter earnings estimates.