Market optimism is being tested by corporate earnings expectations, geopolitical risks and key economic data expected this week.

Wall Street delivered another positive session as the week kicked off, but optimism faded on Tuesday as investors turned their attention to the start of the second quarter earnings season, central bank signals and ongoing geopolitical developments.

The S&P 500 closed 0.72% higher, while the Nasdaq gained 1.1% as technology shares led the advance. However, United States futures slipped into negative territory overnight, with Nasdaq 100 futures giving back much of the previous session's gains.

Bianca Botes, Managing Director at Citadel Global, said investor caution was growing ahead of a busy earnings calendar.

"The tumult on Wall Street set a contrasting tone against the less than buoyant Asian markets, which opened the week with a downturn despite Samsung's optimistic outlook established by a forecasted 19 fold increase in operating profit," Botes said.