Stocks making the biggest moves premarket: Regeneron, Moderna, Dollar Tree and more

Companies are making headlines in premarket trading.

The company's shares fell more than 1% in the premarket after it said its Covid-19 cocktail and similar drugs could be less effective against the omicron Covid variant. There may be reduced neutralization activity of both vaccine-induced and monoclonal antibody conveyed immunity, according to the drugmaker.

Moderna CEO Stephane Bancel told the Financial Times he expects existing vaccines to be less effective against the omicron variant. Oxford University said there is no evidence that current vaccines will not protect against severe disease. Researchers are studying the new variant's ability to evade immunity. Moderna shares fell in the early morning. The shares of BioNTech fell. Pfizer shares increased by 1%. Novavax shares increased in value.

Dollar Tree's shares fell more than 2% in premarket trading after Goldman lowered its rating on the stock to neutral from a buy. The stock is too expensive at the moment, as Dollar Tree's comeback story is now priced in.

Morgan Stanley lowered its rating on SolarEdge Technologies to equal-weight from overweight. Morgan Stanley said that the stock appears to be worth more than it is worth.

The company's shares were slightly lower in the premarket after the U.K. regulators told it to sell Giphy. Competition between social media platforms would be reduced by Meta's acquisition of Giphy.

The shares of meat alternative producer Beyond Meat and plant-based dairy company Oatly each retreated more than 1% in early morning trading after HSBC initiated coverage of the stocks at a "reduce" rating. HSBC said in a report that the growth of the market will be insufficient for many participants to achieve their ambitions.

Jack Dorsey, the CEO of Square, announced that he is stepping down from his position. He was the chief executive at both Square and the social media platform. Square was upgraded to neutral from underperform by Bank of America.