10 things you need to know before the opening bell

Here is what you need to know.

Tensions are mounting on the Korean Peninsula. North Korea held its sixth - and largest - nuclear test over the holiday weekend, provoking US Ambassador to the United Nations Nikki Haley to say North Korean leader Kim Jong Un was "begging for war," Reuters reports.

Stock markets around the world are mixed. Japan's Nikkei (-0.63%) lagged in Asia and Germany's DAX (+0.74%) leads in Europe. The S&P 500 is set to open down 0.39% near 2,467.

Gold is trading at its best level in almost a year. The yellow metal holds little changed at $1,333 an ounce after finishing Monday's session at its highest level since the end of last September.

China's economy is humming along. The Caixin-IHS Markit China composite purchasing manager index (PMI), a measure of activity levels across the nation's manufacturing and services sectors hit 52.4 in August, making for its fastest growth since February.

Australia's central bank holds rates. The Reserve Bank of Australia held its key interest rate at 1.50%, as expected, and said was seeing a slowdown in red-hot housing markets in the country, "especially in Sydney."

Cryptocurrencies are getting smoked after China bans ICOs. The entire cryptocurrency universe has lost more than $30 billion in market cap since Friday as investors run for the exits following China's decision to ban initial coin offerings, a cryptocurrency-based fundraising method.

United Technologies agrees to a $30 billion deal for Rockwell Collins. The deal pays Rockwell shareholders $140 per share, split between $93.33 per in cash and $46.67 in stock, Reuters says.

The maker of Angry Birds is planning an IPO. Finland's Rovio Entertainment announced on Tuesday it is planning to raise about 30 million euros ($36 million) and potentially use its shares to make acquisitions, according to Reuters.

Earnings reports trickle out. HP Enterprise is set to announce its quarterly results after markets close.

US economic data flows. Factory orders and durable goods orders will be released at 10 a.m. ET. The US 10-year yield is down 2 basis points at 2.14%.