Nvidia's huge stock rally is still exerting an outsized influence over the S&P 500 index, reinforcing concerns that broader markets could be hurt if the chipmaking giant's fortunes turn.

JMP Securities believes that the recent decline in Alphabet's (NASDAQ:GOOGL) stock price has fully accounted for the potential impact of antitrust penalties.

U.S. stock index futures were subdued on Monday as caution prevailed ahead of the Federal Reserve's pivotal monetary policy decision later in the week, with investors pricing in a steep reduction in borrowing costs.

The dollar weakened and the yen hit its highest level in more than a year on Monday, as market participants increasingly expected an oversized rate cut by the Federal Reserve later this week.

Oil prices rose in Asian trade on Monday amid expectations of a U.S. interest rate cut this week, though gains were capped by persistent demand worries and weaker China data.

Citi analysts said in a note Monday that Boeing's (NYSE:BA) ongoing labor negotiations may be one of the final hurdles the company must overcome before news becomes more positive.