Did South Park mark the top for weight-loss stocks?

The threat of AI disruption has wreaked havoc upon software stocks over the past few months, with more powerful tools launched by Anthropic a catalyst for the selling. True to form, thanks to some new plugins recently added to Claude Cowork, legal software and publishing companies are facing intense selling pressure.

Anthropic, maker of Claude, rolled out a series of plugins that could be added to Cowork for paying subscribers on Friday. One of which is legal, to “review documents, flag risks, and track compliance.”

Shares of RELX (owner of Lexis Nexis), Thomson Reuters (owner of Westlaw), and Legalzoom.com are getting hammered in premarket trading on Tuesday. One distinction: the first two companies offer proprietary data, which may insulate them a little better from the analytical threat from Claude, while LegalZoom’s business of providing legal services may be more directly threatened by the relatively low barrier to entry of using Claude Cowork instead.

Perhaps these fresh capabilities from Claude explain why iShares Expanded Tech Software ETF dropped more than 2% on Friday and continued to struggle on Monday. Other plugins include productivity, enterprise search, sales, finance, data, marketing, customer support, product management, biology research, and a meta-plugin to create and customize other plugins.

Even without plugins, there have been many tales of legal professionals and laypeople alike turning to chatbots for help in this domain. Per Business Insider, short-seller Andrew Left has turned to Claude to analyze legal documents and draft letters after facing allegations of market manipulation.

Pfizer slipped in premarket trading, down more than 4.5% as of 8:15 a.m. ET, after it reported earnings that beat Wall Street estimates, reaffirmed its full-year guidance, and released mid-stage trial results for its upcoming weight loss drug.

For the last three months of 2025, Pfizer reported:

• Adjusted earnings per share of $0.66, compared to $0.57 analysts polled by FactSet were expecting.

• Revenue of $17.6 billion, compared to $16.8 billion the Street was penciling in.

For the full-year 2026, Pfizer expects:

• Annual adjusted earnings per share to hit between $2.80 to $3.00, compared to $2.97 analysts are currently expecting.

• Annual revenues to hit between $59.5 to $62.5 billion, compared to $60.9 billion analysts are penciling in.

The company also released mid-stage trial results for its monthly weight loss shot, which it recently acquired through its purchase of Metsera. The results showed patients lost over 12.3% of their body weight at 28 weeks.

While the amount lost is in line with products already on the market, it is the first sign that less frequent dosing could still produce results. Late last year, Pfizer won a bidding war against Novo Nordisk, purchasing obesity biotech Metsera for $10 billion.

The pharmaceutical giant is working to reignite growth after demand for its COVID-19 products has waned and as some of its biggest moneymakers get nearer to the end of their patents’ lives. 

Teradyne is up as much as 24% in premarket trading on Tuesday after the company smashed sales estimates in the fourth quarter of 2025 and shared better-than-expected first quarter guidance on Monday evening.

The company, which mainly makes equipment that tests advanced systems like semiconductors, reported:

• Revenue of $1,083 million, topping Wall Street’s forecast of $964 million (consensus compiled by Bloomberg).

• Adjusted earnings per share of $1.80, 33% higher than the $1.36 expected from analysts.

Looking ahead, Teradyne also shared revenue guidance of $1,150 million to $1,250 million and estimated adjusted EPS of $1.89 to $2.25 for Q1 2026, way above analysts’ estimates of $933 million and $1.26, respectively.

In the press release, Teradyne CEO Greg Smith said that the company’s strong growth was “fueled by AI-related demand in compute, networking and memory within our Semi Test business,” also noting that its business groups — Semi Test, Product Test, and Robotics — all showed “sequential growth.”

Driven by strong AI momentum, Teradyne has surged 125% in the past year, and has been doubling down on supporting demand from the AI Data Center equipment market, including forming a joint venture with a high-speed test company Multilane last week. Chip-tester rival Advantest is also up 7% on the news.

Merck reported Q4 results that beat Wall Street estimates but gave full-year guidance below expectations.

For the last three months of 2025, Merck reported:

• Adjusted earnings per share of $2.04, compared to $2.01 analysts polled by FactSet were expected.

• Revenue of $16.4 billion, compared to $16.02 billion the Street was expecting.

For the full-year 2026, Merck expects:

• Merck expects to report annual adjusted earnings per share to hit between $5.00 and $5.15, lower than the $5.27 analysts are currently expecting.

• The company expects annual revenues to hit between $65.5 billion and $67.0 billion, the midpoint of which is below the $67.4 billion analysts are penciling in.

Iconic gaming company Nintendo revealed that it sold around 7 million Switch 2 consoles in the third quarter ended December, topping analysts' average estimates for 6.5 million sales, and pushing cumulative Switch 2 sales past 17 million, making it the "fastest-selling dedicated video game platform" in Nintendo's history, according to the company.

Separately, the predecessor to the Switch 2 quietly became Nintendo’s best-selling console ever, having now sold 155.4 million units since its launch in 2017 according to The Verge, overtaking the mighty Nintendo DS, released in 2004, which sold 154 million units in total.

Heading into the print, Nintendo’s shares rose modestly in trading in Japan — gains that the stock has broadly held onto on Tuesday’s session, adding 1.8%. The ADRs, listed in the US, which have been impacted by currency volatility between USD/JPY, rose 5.7% on Monday.

For the quarter ended December, revenue came in at ¥806.3 billion ($5.2 billion), below estimates of ¥815.7 billion. Margins were also a little light, with operating income coming in at ¥155 billion, below estimates for ¥181 billion, per Bloomberg.

Nintendo maintained its full-year revenue and profit guidance, as well as its forecast of 19 million Switch 2 unit sales for the fiscal year ending March 2026.

The gaming giant's shares had hit a record high last summer following the Switch 2's launch, but are now down ~35% from that peak, with the company’s profitability weighed down by tariffs and rising memory chip costs — a key component in its consoles — as chipmakers prioritize more profitable demand from AI data centers.

Still, higher chip prices "will not have a significant impact in the third and fourth quarter performance," though a prolonged price surge could "put pressure on earnings," President Shuntaro Furukawa said on the earnings call.