Check out the companies making headlines midday Monday:

Dillard's — Shares of the retailer surged more than 32% after one of Warren Buffett's top lieutenants revealed a stake in the company. Ted Weschler's stake is over 1 million shares, or about 5.89% of the outstanding stock, according to a securities filing.

Twitter — Twitter shares rose more than 4% after a Deutsche Bank analyst upgraded the social media stock to buy from hold. "We are now starting to hear more positive feedback in the ad channel and would take advantage of the opportunity to build a position now," said the analyst who also hiked his price target on Twitter to $56 per share from $36 per share. The new target implies a 22% upside over the next 12 months.

Twilio — Twilio popped more than 5% after the cloud communications company said it was buying Segment, a customer data infrastructure firm, for $3.2 billion in stock. The deal is expected to close by the end of 2020.

PepsiCo — An analyst at PepsiCo upgraded PepsiCo to buy from neutral, citing "consistent organic sales growth" and a low operating margin relative to its competitors.  "After nearly five years of relative underperformance, we think now is the time to buy PEP," the analyst said. PepsiCo shares rose nearly 3%.

Levi Strauss — Morgan Stanley upgrade Levi Strauss to overweight from equal weight, sending the stock up 5%. Analysts at the bank noted the company's "impressive revenue acceleration and positive 3Q EPS highlight management's swift response to a pressured retail environment."

DouYu International — Shares of Chinese video live-streaming service DouYu rallied more than 11% on news it will merge with Huya, a video-game publisher based in China, in an all-stock deal. The merger is expected to close in the first half of 2021.

Ford Motor — The legacy auto stock jumped more than 6% after Benchmark upgraded the name to buy from hold. The investment firm said in a note to clients that new products and low inventory should create momentum for the company heading into 2021.

Alphabet — Alphabet shares rose more than 3% after Deutsche Bank hiked its price target on the tech giant to 2,020 per share from $1,975 per share, implying a 34% upside from Friday's close. The analyst said he expects Google Sites revenue growth to accelerate to 12.1% while YouTube revenue remains strong.

Apple — Shares of Apple rose more than 5% ahead of its iPhone launch on Tuesday. Apple is expected to release new iPhones with 5G cellular networks, which touts faster download times.

—CNBC's Michael Bloom, Maggie Fitzgerald and Jesse Pound contributed to this report.