The S&P 500 lost 0.5% on Monday, pulling back from a three-week winning streak. The benchmark index never traded in positive territory but it did cut its intraday losses in half. The Dow Jones Industrial Average (-0.4%) also finished off its low.  The Nasdaq Composite (-0.9%) and the Russell 2000 (-1.0%) did, too, yet they did not fare as well overall.

The S&P 500 utilities (-2.3%), health care (-1.2%), and information technology (-0.9%) sectors weighed on the broader market. Conversely, the financials (+0.7%) sector helped offset losses and it was the only sector to finish in positive territory.

The broader market opened on a lower note, as disappointing trade data out of China stirred ongoing concerns over global economic growth. Specifically, China's exports unexpectedly declined 4.4% year-over-year in December and its imports declined 7.6%.

In addition, the amount of attention surrounding the partial U.S. government shutdown, which is currently the longest in U.S. history with no clear end in sight, also weighed on investor sentiment.

The S&P 500 managed to bounce off its early lows as Citigroup (C 58.93, +2.24, +4.0%) overcame early weakness that was initially attributed to some disappointment over a fourth quarter revenue shortfall that overshadowed better than expected earnings results driven in part by expense savings and a lower tax rate.

Citigroup was down more than 1.0% in pre-market hours but quickly reversed course shortly after the start of the trading session. Its quick turnaround, which several pundits attributed to a discounted valuation, helped lift other bank stocks and the financial space.

There was no coming back for PG&E (PCG 8.38, -9.21), however, after the company disclosed intentions to file for Chapter 11 bankruptcy protection amid possible liability for the California wildfires. The stock consequently plunged 52.4% and was a huge drag on the underperforming utilities sector.

U.S. Treasuries finished mixed with the 2-yr yield decreasing three basis points to 2.52% and the 10-yr yield adding one basis point to 2.71% in a curve-steepening trade. The U.S. Dollar Index lost 0.1% to 95.59. WTI crude lost 2.1% to $50.58/bbl.

Investors did not receive any economic data on Monday.

Looking ahead, investors will receive a couple of economic reports on Tuesday: the December Producer Price Index and the Empire State Manufacturing Survey.  Also, the UK Parliament is expected to hold a widely-watched (and potentially market-moving) vote on the UK Brexit plan around 2:00 p.m. ET.

• Russell 2000 +6.3% YTD
• Nasdaq Composite +4.1% YTD
• S&P 500 +3.0% YTD
• Dow Jones Industrial Average +2.5% YTD