US index futures were lower by a third of a percent on June 3 on concerns over economic growth and escalating trade tensions.

The S&P 500 futures and Dow Jones Industrial Average futures were lower by 0.3%, while Nasdaq 100 futures was down around 0.1% a short while ago.

One of the triggers for the fall has been the projection of lower growth by the Organization for Economic Co-operation and Development (OECD), which has cut its US growth forecast. According to OECD, the US economy will expand by just 1.6% in 2025 against the previous forecast of for around 2.2%. OECD has also cut its global growth projections for a second time this year amid US President Trump's tariff announcement.

OECD said that the global outlook is becoming increasingly challenging. “Substantial increases in barriers to trade, tighter financial conditions, weaker business and consumer confidence and heightened policy uncertainty will all have marked adverse effects on growth prospects if they persist," the report said.

On specific stocks, shares of Constellation Energy were up nearly 11% in pre-market trade on news that the company has reached a 20-year deal to sell nuclear power to Meta Platforms, which will purchase about 1.1 gigawatts of power from Constellation’s Clinton Clean Energy Center in Illinois starting in 2027.

Other Markets Mixed

On the other hand, Asia-Pacific markets ended mixed on shrinking China manufacturing activity in May, with the Caixin/S&P Global manufacturing purchasing managers’ index at 48.3, dropping from 50.4 in April. This decline comes at a time of lower fresh export orders, highlighting the impact of US tariffs.

The Hang Seng Index ended around 1.53% higher while China’s CSI 300 gained around 0.31%. Japan's Nikkei 225 benchmark ended flat and Australia’s S&P/ASX 200 benchmark gained 0.63%. Indian markets too fell, with Sensex down 0.78 percent and the Nifty lower by 0.70 percent as it failed to hold on to early gains.