08:58 AM EDT, 06/23/2025 (MT Newswires) -- US equity futures were flat ahead of Monday's opening bell as traders stayed on the sidelines after the US said it attacked three key Iranian nuclear sites over the weekend.

Dow Jones Industrial Average futures were down 0.1%, while S&P 500 futures and Nasdaq futures were flat.

Investors are monitoring the potential military response from Iran following the weekend attack.

Oil prices were lower, with front-month global benchmark North Sea Brent crude down 0.3% at $75.24 per barrel and US West Texas Intermediate crude 0.6% lower at $73.43 per barrel.

The Composite Purchasing Managers' Index is scheduled for release at 9:45 am ET.

The existing home sales bulletin, slated for 10 am ET, is expected to show home resales at a 3.96 million annual rate for May versus 4 million previously, according to estimates compiled by Bloomberg.

In other world markets, Japan's Nikkei closed 0.1% lower, Hong Kong's Hang Seng ended 0.7% higher, and China's Shanghai Composite finished 0.7% higher. Meanwhile, the UK's FTSE 100 was down 0.2%, and Germany's DAX index was 0.5% lower in Europe's early afternoon session.

In equities, Cidara Therapeutics ( CDTX ) shares were 88% higher pre-bell after the company reported a phase 2b trial of CD388 for the prevention of seasonal influenza in healthy unvaccinated adults aged 18 to 64 met its primary endpoint and all secondary efficacy endpoints for all dose groups.

On the losing side, Dow (DOW) stock was 1.7% lower after BMO Capital cut its rating to underperform from market perform and cut its price target to $22 from $29.