Post Market: S&P 500 Gains and Losses

S&P 500 gainers

Warner Bros. Discovery (WBD) shares jumped 5.4%, locking in the top daily performance in the S&P 500. Wolfe Research upgraded the media giant's stock earlier this week to "peer perform" from "underperform." Although analysts recognized that WBD faces ongoing challenges from declining linear TV revenues, they highlighted several bright spots. Analysts said there is potential for international growth for the Max streaming service, increasing profitability of the direct-to-consumer (DTC) segment, and potential opportunities from industry trends in re-bundling and partnerships.

Shares of Albemarle (ALB), the world's largest lithium miner, added 5.2%. Wednesday's increase extended gains posted by Albemarle stock earlier this week after Australia-based Liontown Resources (LINRF) became the latest lithium producer to scale back production plans as prices for the metal remain under pressure. Albemarle's earnings report, released last week, showed a wider-than-expected quarterly loss but provided details on cost-saving measures, including staff cuts.

Cable TV and internet provider Charter Communications (CHTR) announced an agreement to acquire media mogul John Malone's Liberty Broadband (LBRDA) in an all-stock transaction. Liberty's assets include its subsidiary GCI, Alaska's largest communications provider, and a roughly 32% stake in Charter. The boards of directors at Charter and Liberty approved the deal. Charter shares closed the day 3.6% higher.

S&P 500 losses

Following a sharp downturn on Monday, shares of power management chipmaker Monolithic Power Systems (MPWR) posted the steepest daily decline of any S&P 500 stock for the second time this week, slumping 6.6% Wednesday. The losses followed a report that semiconductor powerhouse Nvidia (NVDA) may omit or cut back on Monolithic's components in its next-generation AI chips.

Shares of Super Micro Computer (SMCI) fell 6.3%, exacerbating a string of losses that have been pummeling the stock since the server and data storage maker said it would push back the release of its fiscal first-quarter earnings report. Supermicro has not announced when it will be able to disclose the results, and the stock faces a possible delisting from the Nasdaq should the delays continue.

ResMed (RMD) shares sank 4.8% as regulatory filings revealed that a pair of top executives and a member of the board of directors had sold shares in the medical device maker. Investors often interpret selling by insiders as a lack of confidence in a company's upcoming performance