Biggest stock movers Monday: RUM, MTSR, and more

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Stock futures edged up Monday morning as reports surfaced that Senate negotiators reached a stopgap agreement to end the longest government shutdown in U.S. history.

Here are some of Monday's biggest stock movers:

BIGGEST STOCK GAINERS

* RUMBLE (RUM [https://seekingalpha.com/symbol/RUM]) +18% - Shares jumped after agreeing to acquire German AI cloud operator Northern Data (OTC:NDTAF [https://seekingalpha.com/symbol/NDTAF]) in an all-stock deal valued at ~$767M. Northern Data shareholders will receive 2.0281 Rumble Class A shares for each Northern Data share, giving them about 30.4% ownership in the combined company. The transaction includes a $150M GPU leasing agreement with Tether, which already holds a 48% stake in Rumble, and $200M in tax support from Rumble. The deal, expected to close by Q2 2026, will also transfer 22,400 Nvidia GPUs to Rumble, with Tether set to become an anchor customer of the expanded AI-focused platform.

BIGGEST STOCK LOSERS

* METSERA (MTSR [https://seekingalpha.com/symbol/MTSR]) -15% - Shares plunged after Novo Nordisk (NVO [https://seekingalpha.com/symbol/NVO]) said it will not raise its takeover bid, clearing the way for Pfizer (PFE [https://seekingalpha.com/symbol/PFE]) to win the acquisition battle. Metsera announced a revised merger agreement with Pfizer valued at up to $86.25 per share in cash, citing the deal as superior due to increasing antitrust risks tied to Novo’s competing offer. The agreement ends a tense bidding war between the two drugmakers over the weight-loss biotech.
* IONIS PHARMACEUTICALS (IONS [https://seekingalpha.com/symbol/IONS]) -13% - Shares dipped even after reporting positive Phase 3 results for its triglyceride-lowering drug olezarsen in patients with severe hypertriglyceridemia. The drug reduced triglyceride levels by up to 72% at six months and sustained effects through one year, with 86% of treated patients reaching levels below the threshold linked to acute pancreatitis risk. Importantly, olezarsen showed an 85% reduction in pancreatitis events, a first for an sHTG therapy, and maintained a favorable safety profile. Despite the strong efficacy data and plans to submit for FDA approval by year-end, shares slid as investors weighed commercial execution and market uptake timelines.

MORE ON METSERA, RUMBLE, ETC.

* Ionis: What Upside Is Left After Shares Rocketed Higher Following Positive Trial Data? [https://seekingalpha.com/article/4837650-ionis-what-upside-is-left-after-shares-rocketed-higher-following-positive-trial-data]
* Metsera Becomes The Prize In Obesity's Biggest Bidding War [https://seekingalpha.com/article/4835591-metsera-becomes-the-prize-in-obesity-biggest-bidding-war]
* Ionis Pharmaceuticals, Inc. (IONS) Q3 2025 Earnings Call Transcript [https://seekingalpha.com/article/4834852-ionis-pharmaceuticals-inc-ions-q3-2025-earnings-call-transcript]
* Novo Nordisk stock rises as drugmaker drops out of bidding war for Metsera [https://seekingalpha.com/news/4519119-novo-nordisk-stock-rises-as-drugmaker-drops-out-of-bidding-war-for-metsera]
* Rumble to buy German AI firm Northern Data for $767 million in an all-stock transaction [https://seekingalpha.com/news/4519108-rumble-to-buy-german-ai-firm-northern-data-for-767-million-in-an-all-stock-transaction]