Oil futures pared their losses by the close on Tuesday, settling with a modest loss, but traders remained concerned over the risk of lower energy demand from China and Europe as well as more oil from Iran.

“The gravity of uncertainty is getting too heavy, and the markets — all of them — are going into protection, avoidance, and caution,” said Richard Hastings, macro strategist at Global Hunter Securities. Crude for August delivery fell 20 cents, or 0.4%, to settle at $52.33 a barrel on the New York Mercantile Exchange, after earlier sinking below $51. It suffered a drop of 7.7% on Monday. Brent crude climbed 31 cents, or 0.6%, to end at $56.85 a barrel. Oil markets overreacted Monday, “and near-term demand is too firm to describe a collapse in demand,” said Hastings. “The widespread ideas that China’s stock-market wreck is about total demand in China” isn’t the case, he said. “However, the bears are in charge right now, and the upside for prices is looking tough,” he said.

Traders have been fretting over the possibility that Greece’s debt woes will hurt energy demand in Europe. “The overall picture remains very grim as the uncertainty over Greece is impacting the appetite for investors,” said Naeem Aslam, chief market strategist at AvaTrade. “But mainly it is the selloff in the Chinese equity market, which is flashing big red lines for investors who are worried that this could be the start of something big — especially after all efforts from [the People’s Bank of China] are not working to halt the selloff.” Still, the International Monetary Fund warned that the U.S. should not raise interest rates yet, and “that may improve demand hopes in the U.S., said Phil Flynn, senior market analyst at Price Futures Group.

Growing oil output from the Organization of the Petroleum Exporting Countries is also a concern. And there’s the threat of additional Iranian oil barrels flooding the market, once its nuclear deal with western powers is completed. Tuesday marked the deadline for an agreement, but talks were expected to continue. Nymex oil prices could easily fall back into the $40s if Iran puts much oil on the market, said James Williams, energy economist at WTRG Economics.

Late Tuesday, the American Petroleum Institute will issue weekly U.S. oil inventory data and the U.S. Energy Information Administration’s report follows Wednesday. Analysts polled by Platts expect crude supplies to show a weekly decline of 1.1 million barrels. In a monthly report Tuesday, the EIA raised its 2015 forecast for West Texas Intermediate crude prices, but cut the outlook for Brent prices.