1. Waiting for the Fed

Investors are on tenterhooks ahead of the annual gathering of Federal Reserve members and other central bankers at the Jackson Hole Economic Symposium in Wyoming, which gets underway today. Fed chair Janet Yellen will be speaking at the event tomorrow.

"If markets are waiting for Jackson Hole the good news is that, unlike Godot, Janet Yellen really will turn up," said Kit Juckes, a strategist at Societe Generale. "I doubt she's going to say anything that radically alters market sentiment, but that's another story."

2. Global stock market overview

The negative mood from Wednesday has extended into today.

U.S. stock futures are drooping. European markets are slumping - French and German stocks are down 1%. And Asian markets are ending the day mostly weaker, except for Taiwan, which managed to pop up by 1.1%.

3. Oil recovers after sharp selloff

West Texas and Brent rebounded on Thursday after a surprise build in U.S. inventories in the prior session drove prices down 2.8% and 1.8%, respectively.

OPEC is set to hold an informal meeting to again discuss an output freeze late next month and hopes for an agreement sent oil soaring nearly 25% in recent weeks.

However, analysts and traders remain skeptical the meeting would result in a coherent effort to reduce the global glut with many experts dismissing the possibility that OPEC could freeze production, let alone cut output.

U.S. crude oil futures gained 0.49% to $47.00 at 9:52AM GMT, while Brent oil rose 0.45% to $49.27.

4. Earnings and economics

Many big companies are reporting results before the open, including a range of retailers.

Dollar General (DG), Dollar Tree (DLTR), Movado Group (MOV), Sears Holdings (SHLD), Tiffany & Co (TIF) and TD Bank (TD) are all releasing their earnings.

On the economic side, the U.S. Department of Labor is releasing its weekly jobless claims data. According to market data provider Briefing.com, initial jobless claims have been below 300,000 each week for the last 76 weeks. That hasn't happened since 1970.