Stocks ended Monday's choppy session mixed as renewed coronavirus concerns outweighed ongoing vaccine optimism following increased lockdowns and travel restrictions in the United Kingdom due to a new infectious COVID strain was identified. Health experts estimate that the new strain is 70% more transmissible that the earlier version of the virus sampled in the country.

Increased coronavirus concerns, however, were slightly outweighed following news that Washington lawmakers had reached a deal for a $900 billion stimulus package. The new bill includes another round of direct payment checks, enhanced federal unemployment benefits, and funds for small businesses and nationwide vaccine distribution. Notably, less bipartisan favored relief proposals like state and local government aid and coronavirus liability protections for businesses were not included in the new bill.

Congress is set to vote on the proposal Monday evening.

Here's how the market settled to open the shortened holiday week:

S&P 500 Index (SPY  ): -0.39% or -14.47 points to 3,694.94

Dow Jones Industrial Average (DIA  ): +0.12% or +36.94 points to 30,215.99

Nasdaq Composite Index (QQQ  ): -0.1% or -13.12 points to 12,742.52

For Stocks, Tesla (TSLA  ) fell as much as 6% following its first day as part of the S&P 500 Index. The electric carmaker became the largest company ever added to the market benchmark and now ranks as sixth overall in the index; the stock is behind Alphabet (GOOG  ) but ahead of Berkshire Hathaway (BRK.A  ). Big banks--Bank of America (BAC  ), Citigroup (C  ), Goldman Sachs (GS  ), JPMorgan Chase (JPM  ), Morgan Stanley (MS  ) and Wells Fargo (WFC  )--charged forward Monday following the Federal Reserve's decision to allow lenders to resume share buybacks in the first quarter of 2021. Airline and cruise names--American (AAL  ), Carnival (CCL  ), Delta (DAL  ), Norwegian (NCLH  ), Royal Caribbean (RCL  ), Southwest (LUV  ) and United (UAL  )--all sunk on Monday following increased global travel restrictions.

For Sector Performance, sectors on the S&P ended Monday's session mostly lower, with only Financials (XLF  ) and Information Technology (XLK  ) closing in positive territory. The session's biggest losers included Energy (XLE  ), Utilities (XLU  ) and Consumer Staples (XLP  ), each declining over 1%.

For Commodities and Currencies, the U.S. Dollar (UUP  ) rose on Monday as the new viral strain in the U.K. increased the greenback's attractiveness. The dollar index, which tracks the currency against other global rivals, rose as high as 91.022 during the session, but fell to 90.226 in midday trading. Bitcoin fell almost 3% after climbing to a record high of $24,298.04 on Sunday, propelled by risk optimism. The cryptocurrency declined to under $22,800 on Monday. Gold (GLD  ) fell lower on Monday as market sentiment became more uncertain about near-term economic recovery and the dollar outweighed the yellow metal for Monday's 'safe haven.' Spot gold fell 0.2% to $1,877.83 per ounce, while U.S. gold futures settled 0.3% lower at $1,882.80 per ounce. Crude oil futures also fell on Monday as demand outlooks weakened under the weight of renewed coronavirus concerns. International benchmark Brent Crude slipped 3.5% to $50.41 per barrel, while domestic benchmark West Texas Intermediate's (USO  ) January contract decreased 2.77% to $47.74 per ounce. The benchmark's February contract also fell 3.7% to $47.41 per barrel.

For Tuesday, investors are likely to react to a passed U.S. stimulus measure as well as December's consumer confidence index reading, which is expected to slightly increase.