By Yasin Ebrahim

Investing.com – The S&P 500 rebounded Monday, led by tech as investor risk appetite returned following last week’s slump amid worries about the impact of the new Omicron Covid-19 variant.

It rose by 1.3%. The Nasdaq saw a gain of 1.9%, or 236 point.

Big tech led the broader market rebound, with Facebook (NASDAQ:), Google-parent Alphabet (NASDAQ:), Amazon (NASDAQ:), Microsoft  (NASDAQ:) and Apple (NASDAQ:) ending in the day higher.

Apple gained more than 2% as HSBC increased its price target. This is because supply chain issues which have impacted on production are likely to diminish.

After Twitter announced Jack Dorsey’s resignation as CEO, the stock price of Twitter fell more than 1%. Parag Agrawal, Twitter’s chief technology officer, will succeed Dorsey. Stock initially rose in the media.

“I’ve decided to leave Twitter because I believe the company is ready to move on from its founders,” Dorsey said in a statement.

Investor sentiment was helped when vaccine companies indicated that they would adjust the Covid-19 vaccines to combat Omicron Covid.

Moderna (NASDAQ:) It said that it would launch Omicron vaccine reformulated by the end of next year. This sent its shares up more than 11%.

According to health experts, it will take approximately two to three weeks for information to be available about Omicron’s transmissibility or severity.

The rise of Tesla and a rebounding in leisure stocks such as Travel and Leisure, led to consumer discretionary being one of the top sectors that gained the most on the day. Expedia (NASDAQ:), Marriott International (NASDAQ:), and Royal Caribbean Cruises (NYSE:).

Tesla (NASDAQ: ) saw a more than 5 percent jump as Tesla looks to abandon its normal strategy of increasing electric vehicle deliveries during the fourth quarter in order to reduce costs.

Tesla chief executive Elon Musk told the company’s employees not to ramp-up deliveries in the third quarter, and focus on the keeping costs low, CNBC reported, citing a recent memo.  

Petroleum was in high demand after the worst-ever daily oil price drop on Friday. The reason for the surge was that oil prices were soaring on fears that OPEC, its allies and others could defer plans to raise production due to concerns over the effect of Covid-19’s new omicron form on energy demand.

“In our view, there is much to suggest that OPEC+ will not initially step up its oil production any further. This is presumably also why oil prices today have gained by around 5%,” Commerzbank said ahead of the OPEC+ meeting on Dec. 2.

Also, Roku (NASDAQ) – Recent losses were more than 1% higher. But Benchmark managed to buck the trend of Wall Street negative commentary and kept its stock rating at a buy. 

“|[W]e have a markedly different view on some of the information being filtered into the marketplace,” Benchmark said, citing recent upbeat channel checks. “[O]Our channel checks show that Roku TVs are in greater demand at Best Buy and Walmart than we thought. We also believe that a Google-Roku solution could be possible, even though there is a temporary blackout.