Check out the companies making the biggest moves midday Wednesday:
Moderna — Shares of Moderna surged 8.28% after the drug maker announced it will partner with Merck to jointly develop and sell a cancer vaccine. Moderna's vaccine is being studied in combination with Merck's Keytruda to treat patients with high-risk melanoma in a Phase 2 trial.
Norwegian Cruise Line Holdings — Shares of Norwegian rose 11.61% after UBS upgraded the cruise operator to a buy and said its shares can rally 30% given the significant improvement in bookings in its third-quarter preview. Competing stocks Royal Caribbean added 11.48%, and Carnival gained than 10.09%.
T. Rowe Price — Shares of T. Rowe Price tumbled 5.14% after the financial firm said preliminary net outflows for the third quarter were $24.6 billion, bringing preliminary year-to-date net outflows to $44.6 billion. It reported preliminary month-end assets under management of $1.23 trillion as of Sept. 30.
PepsiCo — Shares of the snack and beverage maker jumped 4.18% after the company reported profits and revenue that topped analyst expectations. Pepsi also raised its guidance for the year as it was able to successfully raise prices on its products.
Lyft — Lyft shares gained 5.59% following an upgrade from Gordon Haskett to buy from hold. The firm said the stock is trading at attractive levels and should benefit as driver supply improves. The upgrade came after shares fell Tuesday as the Labor Department proposed a change to how gig workers are classified.
Philips — Netherlands-based Philips fell 11.67% to a 52-week low after it said third-quarter core profit would be down about 60% from last year. The health tech company also reported a hit of about $1.3 billion to the value of its respiratory care offering.
Cameco — Shares of the uranium producer plunged 13.63% after Cameco signed an agreement with power plant operator Brookfield Renewable Partners to buy Westinghouse Electric in a deal worth $7.9 billion, including debt. Brookfield Renewable Partners slid nearly 2%.
El Pollo Loco — El Pollo Loco's stock jumped 15.71% after the restaurant operator announced a $1.50 per share special dividend Tuesday. It also announced a new share repurchase program worth up to $20 million.
KnowBe4 — Shares of KnowBe4 rallied 12.69% after the Wall Street Journal reported the cybersecurity firm is close to finalizing a deal to be bought by private equity firm Vista Equity Partners. The deal is worth about $4.5 billion, people familiar with the matter told the paper.
Rocket Lab — Shares dropped 4.53% after Credit Suisse initiated coverage of the space stock with an underperform rating, citing a challenging growth trajectory ahead for the industry. The firm said Rocket Lab has roughly 30% downside from here.
American Airlines — American Airlines' stock rose 3.59%, a day after the carrier said its third-quarter sales likely came in better than it previously expected. Revenue for the three months ended Sept. 30 will be up 13% from the same period of 2019, when it brought in $11.91 billion, American Airlines said.
— CNBC's Tanaya Macheel, Samantha Subin, Alex Harring and Sarah Min contributed reporting.