U.S. stocks languished in negative territory Monday, as their struggle to break into positive territory were unsuccessful, with investors remaining jittery in the wake of disappointing trade data from China and Greek debt drama.

Higher oil prices were lifting energy stocks, but not enough push the market into the green, while risk-aversion was evident from rallying government bonds and gold.

Oil prices were driving higher, with West Texas Intermediate crude (CLH5) up $1.50 to $53.18. 10-year Treasury yields, which move inversely to prices dropped 2 basis points to 1.94%. Gold edged up 0.4% to $1,239 an ounce.

Read: Oil prices volatile after weak China trade data, rig-count drop

The S&P 500 (SPX) hovered just below its previous closing level, with six of its main 10 sectors trading lower. Energy stocks rose, while healthcare and consumer staples stocks led the losses.

Financials were lower amid reports that the strong dollar could hurt bank balance sheets due to a planned surcharge by U.S. regulators.

The Dow Jones Industrial Average (DJI) was slightly lower, with two-thirds of its 30 components trading lower.

The Nasdaq Composite (RIXF) also edged down.

John Manley, chief equity strategist at Wells Fargo, noted that deterioration in earnings expectations on the backdrop of the rising dollar and deflation fears are behind recent market volatility.

“At the moment, forward price-to-earnings ratios are ok, not a reason to buy or to sell. We have to get through earnings malaise and see expectations rise, for markets to go higher,” he added.

Colin Cieszynski, chief market analyst at CMC Markets, attributed today’s Wall Street jitters to overseas events, such as trade data from China and Greece’s posturing with the European Central Bank.

“There is also a realization that the Fed will raise rates this year. Current volatile environment favors short-term investors, who can take advantage of price swings, while long-term investors are on the sidelines, as valuations are pretty high,” Cieszynski added.

Concerns over what will happen to Greece and its debt weighed on markets.

Greece’s Prime Minister Alexis Tsipras on Sunday dismissed the country’s European Union and International Monetary Fund bailouts and said he wouldn’t ask EU leaders for any extension. The country has until Feb. 16 to make the request. The Stoxx Europe 600 dropped 1%, and the Greece ASE Composite Index slid 6% on Monday.

Read: Greek jitters, China data knock Europe stocks sharply lower

Alan Greenspan believes “it’s just a matter of time” before Greece leaves the eurozone, because he can’t see that anyone will be willing to put up more loans to bolster the country’s economy, the former Federal Reserve chairman told the BBC on Sunday.

Read: Europe’s revolt isn’t just in Greece or Spain

Bad news from China: Piling on the pressure for markets, surprise trade data out of China showed sluggish demand from abroad and home. In January, exports slid 3.3% and imports dived more than 19%, leaving a hefty trade surplus for the month.

“This can surely mean only one thing — China will start devaluing its currency soon (engaging in the global currency war),” said Nour Al-Hammoury, Chief Market Strategist at ADS Securities in Abu Dhabi, in a note.

More than 60 companies in the S&P 500 will report this week, but Monday’s schedule is light. Hasbro Inc. (HAS) posted fourth-quarter adjusted earnings of $1.22 per share and revenue of $1.3 billion. The toy maker also said it would buy back up to $500 million in stock. Shares jumped in early trade.

Alcoa Inc.(AA) shares slumped, after J.P. Morgan downgraded the stock to neutral from overweight on concerns about deteriorating fundamentals in aluminum and worry that U.S. premiums will start to track the slide seen of late in Europe.