Check out the companies making headlines in midday trading.

Moderna – The drugmaker saw its stock soar 19.6% after the company issued promising data about its cancer treatment. Moderna announced that its experimental melanoma vaccine combined with Merck cancer treatment Keytruda cut the risk of skin cancer recurrence or death by 44%, compared with a treatment of only Keytruda.

First Solar – The solar stock added 4.5% following an announcement on Monday that it will replace Fortune Brands Home & Security in the S&P 500. Fortune Brands, which is spinning off a division, will replace First Solar in the S&P MidCap 400 index. It added 2.1%

Pfizer – The Covid vaccine maker gained 1.7% after Goldman Sachs upgraded the stock to buy from neutral, saying progress in other areas make the firm confident the stock will perform even as the need for its pandemic-related offerings decreases.

Oracle – Shares of the software company slipped about 1%. Late Monday, the firm reported better-than-expected results in its fiscal second quarter as cloud infrastructure revenue jumped. However, Oracle did issue a lighter earnings forecast than analysts had predicted.

Fiverr – Shares of the freelance services marketplace operator gained nearly 2% after Citi initiated coverage of the stock with a buy rating. The firm said stocks such as Fiverr already reflect concerns about macroeconomic weakness.

United Airlines – The airline stock shed 6.9% following news that it's purchasing at least 100 Boeing 787 Dreamliners to replace its less fuel-efficient planes. The aircrafts are slated for delivery between 2024 and 2032. Boeing shares added about 0.5%.

Pinterest – Shares of the social media company climbed 11.9% after Piper Sandler upgraded Pinterest to overweight from neutral. Analyst Thomas Champion highlighted advertisers' positive view on Pinterest and a potential stock buyback as reasons for the upgrade.

Amazon and Meta – Shares of Amazon and Meta rose 2.1% and 4.7% respectively after Goldman Sachs named the stocks their top picks of 2023.

Mobileye – The automated driving company jumped 4.9% after JPMorgan initiated the stock as overweight, saying it had "robust fundamentals."

Norwegian Cruise Line – The cruise giant shed 2.8% after UBS downgraded the stock to neutral from buy. The firm said the stock's risk/reward was less attractive following its fall rally.

Block – Block rallied more than 7% after Piper Sandler upgraded the stock to overweight from neutral, saying it sees "years" of consistent earnings growth and revenue.

Hayward Holdings – Shares of the pool stock traded up 1.5% after Stifel initiated the stock as a buy and said it had solid growth prospects.

— CNBC's Michelle Fox, Yun Li, Jesse Pound, Tanaya Macheel, Samantha Subin and Carmen Reinicke contributed reporting.