10 things you need to know before the opening bell

Here is what you need to know.

The Fed's Jackson Hole Symposium begins. This year's conference, titled "Designing Resilient Monetary Policy Frameworks for the Future," will be highlighted by Federal Reserve Chair Janet Yellen's Friday speech that is expected to lay the groundwork for Fed policy going forward.

German business confidence weakened in August. The latest Ifo Business Climate Index slid from 108.3 points in July to 106.2 points in August, "suggesting the German economy has fallen into a summer slump," Prof. Dr. Clemens Fuest, the president of the Ifo Institute, writes.

The S&P 500 has gone 33 straight sessions without a daily move of at least 1%. Jim Reid, Deutsche Bank's managing director and head of global fundamental credit strategy, wrote in a note to clients on Thursday: "Markets continue to behave like they've eaten too much cake and need to lie in the corner and do nothing in order to recover. Inactivity rules."

Central banks aren't buying gold the way they used to. A research note sent out by Matthew Turner's team at Macquarie said central banks bought an estimated 166 tonnes of gold in the first half of the year, down from 179 tonnes through the first half of 2015.

Apple might owe Europe billions of dollars in taxes. The European Commission is expected to impose a judgment against the tech giant in the next few months; Apple is accused of striking a sweetheart tax deal with Ireland, and, per the Financial Times, JPMorgan says the judgment could be as high as $19 billion.

A new study should have Coke and Pepsi terrified. The American Journal of Public Health found that the sugary-beverage tax of a penny per ounce in Berkeley, California, lowered consumption there by 21%.

Uber is testing flat fares that make it almost as cheap as a bus. The ride-hailing company is giving some riders the option of buying a package of 20 trips for $20 or 40 trips for $30 for September. If riders go above the number of prequalified rides - or above the $20 ride limit - then they start paying out of pocket.

Stock markets around the world are lower. Germany's DAX (-0.9%) leads the losses in Europe after China's Shanghai Composite (-0.6%) paced the decline in Asia. S&P 500 futures are down 3.25 points at 2,171.75.

Earnings reporting remains light. Sears, Tiffany & Co., and Dollar Tree will report ahead of the opening bell, and GameStop will release its quarterly results after markets close.

US economic data picks up a bit. Initial jobless claims and durable orders will be released at 8:30 a.m. ET, and Markit US Services PMI will cross the wires at 9:45 a.m. ET. The US 10-year yield is down 2 basis points at 1.54%.