Check out the companies making headlines in midday trading:

Berkshire Hathaway — Class A shares added 0.6% following the release of first-quarter results and the annual shareholders meeting on Saturday. Berkshire posted a 39% yearly jump in operating profit, while cash holdings are approaching $200 billion.

Micron Technology — The Boise, Idaho-based semiconductor company jumped 4.5% following an upgrade from Baird to outperform from neutral. The analyst cited valuation, incrementally positive trends in dynamic random-access memory, or DRAM, pricing and growing demand for high-bandwidth memory.

Spirit Airlines — The discount carrier slid 9% after posting a loss of $1.46 per share in the first quarter, wider than a FactSet consensus estimate from analysts of a $1.45 loss per share. Revenue matched expectations. Spirit also forecast second-quarter revenue between $1.2 billion and $1.34 billion, below a FactSet estimate of $1.46 billion.

Paramount — Shares popped 3.3% following a report that the owner of Paramount Pictures and CBS Entertainment Group began formal acquisition negotiations with a group led by Sony Pictures Entertainment and Apollo. Elsewhere, Warren Buffett said over the weekend that he sold the entire Berkshire stake in Paramount at a loss.

United States Steel — The Pittsburgh-based steelmaker saw its shares rise more than 2% after Morgan Stanley upgraded it to overweight from equal weight. U.S. Steel shares have room to rise due to internal improvements, even if the Nippon Steel buyout deal collapses, Morgan Stanley said in a note.

Medical Properties Trust — Shares dropped nearly 7% after a major tenant of the company’s, the physician-owned hospital operator Steward Health Care, filed for Chapter 11 bankruptcy.

EHang Holdings — The autonomous aircraft stock surged 9% after Morgan Stanley initiated coverage with an overweight rating, calling the company “primed for takeoff” amid growing regulatory and governmental support in China.

Tyson Foods — The food processor saw its shares drop 6% after posting revenue of $13.07 billion in its fiscal second quarter, which was short of the $13.15 billion expected by analysts polled by StreetAccount. Tyson also reported earnings of 62 cents per share, beating estimates of 39 cents per share.

Bausch + Lomb — Shares of the eye health stock popped 4.4% on the back of a Morgan Stanley upgrade to overweight from equal weight. Morgan Stanley said the market is likely overlooking the Canadian-based company’s progress on improving core profit margins.

Coinbase — The crypto stock rose 2.5% after Barclays hiked its price target, implying less downside ahead for shares. The bank’s move comes after Coinbase reported better-than-forecast earnings last week.

Li Auto — The Chinese electric vehicle maker gained 2.3% after reporting strong orders for its L6 vehicles. In the April 18 to May 5 period, orders for L6 vehicles exceeded 41,000, according to a Weibo post.

Victoria’s Secret — Shares of Victoria’s Secret was almost 2% higher after opening about 0.4% lower. Morgan Stanley downgraded the intimate apparel maker to underweight due to expectations for negative earnings per share revisions. The Wall Street bank also trimmed its price target.

— CNBC’s Alex Harring, Jesse Pound, Samantha Subin, Hakyung Kim and Sarah Min contributed reporting.