CNBC.com's MacKenzie Sigalos brings you the day's top business news headlines. On today's show, CNBC.com's Annie Palmer breaks down the effort among workers in an Alabama Amazon warehouse to unionize. Plus, CNBC.com's Pippa Stevens dives into one of the defining stock market themes of 2020, and whether or not it will continue in 2021.

Amazon moves closer to facing its first unionization vote in six years

Amazon and a retail union looking to represent some of the company's Alabama warehouse workers reached an agreement Tuesday on the size of a potential bargaining unit, bringing the union one step closer to an election.

If successful, the Alabama union drive would establish the first-ever labor union representation at a U.S. Amazon facility.

Unions have a stronger foothold among some of Amazon's European workforce, but the company has largely managed to thwart organizing efforts in the U.S. However, in recent years, protests tied to Prime Day and other events, as well as the coronavirus pandemic, have hinted at rising organizing efforts across the country. Amazon hasn't faced a substantial union vote since 2014, when repair technicians at a Delaware warehouse failed to garner enough votes to form a union.

Jim Cramer says stay-at-home trade is back on — 'Lockdown is where we're headed'

The stay-at-home trade has returned to Wall Street despite the U.S. launching its Covid-19 vaccination campaign, revealing some insight into how investors gauge the economic bounce back in the near term, CNBC's Jim Cramer said Monday.

"The recovery stocks are handing the baton back to the lockdown winners because lockdown is where we're headed," the "Mad Money" host said, bemoaning ever-increasing coronavirus transmissions and hospitalizations across the country.

"Nobody wants to shut down the economy … even partially, but with infections exploding, hospitals overwhelmed and a horrifying death toll, even the Covid doubters who think that it was just a hoax are starting to take the virus seriously."

Trump's attack on Covid relief bill could lead to government shutdown, lapse in unemployment aid

President Donald Trump's last-second opposition to a coronavirus relief and federal funding bill already passed by Congress threatens to torch jobless benefits for millions of Americans and shut down the government during a deadly public health crisis.

After weeks of no involvement in congressional efforts to pass another aid package, the outgoing president shocked Washington on Tuesday night by calling the bill a "disgrace" and pushing lawmakers to increase $600 direct payments to $2,000.

While he did not explicitly say whether he would veto the bill or simply refuse to sign it, Trump said the "next administration will have to deliver a Covid relief package" if Congress does not send him revised legislation.