US open: Amazon.com throws grocers into disarray amid derivatives expiry

At 1706 BST the Dow Jones Industrial Average was higher by 0.03% or 6.3 points to 21,365.52, while the S&P 500 was slipping 0.10% to 2,430.02 and the Nasdaq Composite dipped 0.28% to 6,148.61.

"It's difficult to read too much into moves in equity markets with today being the expiry of June futures and options – otherwise known as quadruple witching – likely playing a big role," said Craig Erlam, senior market analyst at Oanda.

From a sector standpoint, the biggest losses were being sustained by: Non-ferrous metals (-4.88%), Food retailers (-4.52%), Basic Resources (-4.04%), Food and drug retailers (-4.04%) and Footwear (-2.77%).

Grocers and discounters were among the most heavily traded issues, with stock in Wal Mart down by 6.03%, alongside falls of 12.65% in Kroger and an 9.29% fall for Target.

That followed news that Amazon.com had clinched the acquisition of rival Whole Foods for $13.7bn in cash, sparking worries in the wider sector about the scope for intense competition.

Consumer sentiment in the States soured in the wake of ex-Federal Bureau of Investigation chief James Comey's Senate testimony, the results of the most widely-followed gauge of the consumer climate revealed.

The University of Michigan's consumer confidence gauge retreated only modestly at the start of June, slipping to 94.5 from an end of May level 97.1.

That was worse than the consensus forecast for an unchanged print of 97.1.

Homebuilders in the US broke ground on 5.5% fewer homes in May, with starts running at an annualised pace of 1.092, according to the Department of Commerce.

Economists had expected the annualised pace of housing starts to rise to 1.223m.

Meanwhile, oil prices were trading up ahead of Baker Hughes oil rig count data at 1800 BST, with West Texas Intermediate gaining 0.60% to $44.73 a barrel on the ICE.

Investors were also eyeing a Q&A session at the Park Cities Rotary Club in Dallas at 1745 BST, as Federal Reserve President Rob Kaplan will be attending.

Google's Alphabet was also in the spotlight following a report it could be fined more than €1bn by the European Commission over allegations it abused its position in the search engine market.