CNBC.com's MacKenzie Sigalos brings you the day's top business news headlines. On today's show, Grant Thornton Chief Economist Diane Swonk explains why the $300 weekly unemployment supplement does more to help the economy than $600 direct checks. Plus, the 'After Hours' team breaks down how Sony's PlayStation 5 launch succumbed to bots, scalpers, and shortages.

Congress agrees to a Covid stimulus deal. Here's who's likely eligible for a $600 check and when you'll get it

Under the new Covid relief package, at the full benefit amount, a family of four could potentially receive $2,400, though the income criteria for the second stimulus check have not yet been released.

However, if it follows the same structure as the March CARES Act, those qualifying for a full stimulus payment include individuals earning up to $75,000, or $112,500 as head of household and $150,000 as a married couple filing jointly. For every $100 earned over these income thresholds, payments are reduced by $5, up to a specified maximum income.

However, it is worth noting that the CARES Act checks were worth twice as much, so it is not yet clear how the $600 checks will be phased out.

'Out of control' Covid strain makes UK a global pariah as countries impose travel bans

A highly contagious new variant of the coronavirus is causing countries in Europe and elsewhere to block travel from Britain.

The U.K. last week warned of a new coronavirus variant that is thought to be up to 70% more transmissible than the original strain of the disease. According to the World Health Organization, the new variant has so far been identified in Denmark, the Netherlands and Australia.

News of the strain forced the British government to backtrack on plans to let families mix over Christmas, locking down London and other areas in southern England where infections by the Covid mutation are heavily concentrated.

Tesla shares fall 6% as it enters the S&P 500 with 1.69% weighting, fifth largest

Tesla's S&P 500 inclusion is official and its debut is not looking so good.

The shares shed 6.5% on Monday as investors who bought the stock in anticipation of its entry into the benchmark cashed in. The stock fell to its session low following a report that Apple is moving forward with its electric vehicle production.

The electric car maker has a 1.69% weighting in the index, the fifth largest. It is the sixth biggest company in the large-cap benchmark when counting the share classes of Alphabet together.