U.S. stock markets closed lowered Tuesday as increased tensions between Iran and the United States are making investors nervous over 2020's outlook. All three market indices closed in the negative territory despite news that the U.S. trade deficit fell to a more than three-year low in November as imports declined further due to the ongoing trade war between U.S. and China. The U.S. government reported that the trade deficit for goods and services declined to $43 billion for November, down from October's $46.9 billion.

Here's how the market settled Tuesday:

S&P 500 Index (SPY  ): -0.28% or -9.10 points

Dow Jones Industrial Average (DIA  ): -0.42% or -119.70 points

Nasdaq Composite Index (QQQ  ): -0.03% or -2.88 points

Wall Street strategists warned market participants that 2020 will be dominated by politics, not trade, as the coming U.S. presidential election is fast approaching. This will be a new focus from the trade-focused volatility that trapped investors all throughout 2019.

In U.S. Economic News, the Institute for Supply Management's non-manufacturing index released Tuesday reported that the services sector expanded in December to 55, up from November's reading of 53.9. This rise in activity comes from businesses feeling relief from the burden of the ongoing trade war as the U.S. and China have agreed to sign a partial trade agreement on Jan. 15.

In Stock Sector News, all 11 sectors plummeted in Tuesday's trading period. The share losses were as follows: Real Estate -1.20%, Consumer Staples -0.73%, Financials -0.67%, Health Care -0.24%, Materials -0.21%, Energy -0.21%, Utilities -0.20%, Consumer Discretionary -0.13%, Industrials -0.12%, Information Technology -0.11% and Communication Services -0.04%.

Lastly, in Commodity and Currency News, oil prices continue to drop as crude is beginning to stabilize from its initial spike last week. West Texas Intermediate (USO  ) declined just over -0.10% and Brent Cruse (BNO  ) fell almost -0.30%. The price per barrel for the commodity still remains well over $60. Gold is also starting to decline as market participants move away from their initial gut reactions to the recent geopolitical conflict. The price per ounce for the metal fell almost -0.40% in trading Tuesday. Finally, the U.S. Dollar gained some strength today, with the DXY Index increasing +0.35%.