Evaluating the Sustained Momentum of Top Large-Cap Gainers in Q4 2025: Are Rivian, Moderna, and Rocket Lab Stock Buys for 2026?

The fourth quarter of 2025 delivered a mixed bag of outcomes for three high-profile stocks-Rivian, Moderna, and Rocket Lab-each navigating distinct sector dynamics and strategic inflection points. As investors look ahead to 2026, the question of whether these companies can sustain their momentum hinges on their ability to capitalize on growth catalysts and sector tailwinds. This analysis evaluates their Q4 2025 performance, key strategic initiatives, and the broader market forces shaping their trajectories.

Rocket Lab: A Space Sector Rebound with High Stakes

Rocket Lab's Q3 2025 results underscored its resilience, with revenue surging 48% year-over-year to $155 million and a GAAP loss of -$0.03 per share that beat analyst expectations by 71.3%. The company's Q4 guidance of $170–180 million in revenue further solidified investor confidence, while price targets from Stifel and Keybanc were raised to $75. This momentum carried into Q4 2025, where Rocket Lab's stock climbed 111% year-to-date, buoyed by high-profile missions for the Japan Aerospace Exploration Agency and the U.S. Space Force.

A pivotal catalyst for 2026 is the Neutron rocket, a medium-lift vehicle slated for its maiden flight in the first half of the year. Neutron is designed to carry up to 13,000 kilograms to low Earth orbit, positioning Rocket Lab to compete for larger commercial and government contracts. Analysts note that replicating the operational success of its Electron rocket with Neutron could transform Rocket Lab's revenue profile, particularly as the space sector anticipates a blockbuster 2026 IPO for SpaceX, which could push valuations for publicly traded space peers higher. With a $1.1 billion order backlog and a 1,200% three-year stock gain, Rocket Lab appears well-positioned to leverage these tailwinds.

Rivian: A "Prove-Me" Year for the EV Innovator

Rivian's Q4 2024 results marked a turning point, with a record $170 million gross profit-a stark contrast to its $606 million loss in Q4 2023. The company's Q3 2025 revenue of $1.6 billion, up 78% year-over-year, further signaled progress, driven by cost reductions, regulatory credit sales, and a 15% decline in operating expenses. Analysts project $6.9 billion in 2026 sales and a share price of $39.27, reflecting optimism around the R2 model's launch in early 2026.

The R2, an affordable EV targeting the U.S. market, is critical to Rivian's growth strategy. Wedbush Securities' Dan Ives called 2026 an "inflection year" for the company, emphasizing that the R2 could boost deliveries and validate Rivian's autonomy roadmap. Additionally, Rivian's software business, which contributes 25% of total revenue, and its vertical integration in autonomous driving-such as the development of a proprietary AI chip-offer long-term margin upside. However, risks persist, including low gross profit margins and regulatory uncertainties. For Rivian to succeed, the R2 must resonate with price-sensitive consumers while maintaining the brand's premium positioning.

Moderna: Navigating Biotech Challenges with Strategic Pivots

Moderna's Q4 2024 performance was mixed, with revenue declining 65.6% year-on-year to $966 million and a GAAP loss of $2.91 per share. However, the company's 2026 strategy outlines a path to recovery, targeting 10% revenue growth through expanded seasonal vaccine offerings and investments in oncology and rare diseases. Moderna plans to leverage cash flow from approved products like Spikevax and mRESVIA to fund late-stage trials for influenza and flu/COVID combination vaccines.

Sector tailwinds in 2025, including a resurgence in biotech deal-making and improved manufacturing efficiency, have bolstered optimism. Moderna's new facilities in the UK, Canada, and Australia are projected to enhance gross margins by 10% over three years. Analysts also speculate that a potential strategic acquisition or partnership could ignite the stock, as seen in Q4 2025 when deal talk drove a 3% post-earnings rally. While Moderna's 2025 guidance fell short of expectations, its 2026 pipeline and cost-cutting measures position it to capitalize on a more favorable biotech funding environment.

Conclusion: Balancing Catalysts and Risks

Rocket Lab, Rivian, and Moderna each face unique challenges in 2026. Rocket Lab's Neutron rocket and space sector optimism make it a compelling long-term bet, though execution risks remain. Rivian's R2 launch and software-driven margins could redefine its EV narrative, but regulatory and economic headwinds must be navigated. Moderna's biotech turnaround hinges on vaccine demand and strategic deals, with its manufacturing efficiency offering a margin buffer.

For investors, the key lies in aligning these companies' growth catalysts with sector trends. Rocket Lab and Rivian appear better positioned to capitalize on their respective inflection points, while Moderna's success will depend on its ability to diversify beyond vaccines. As 2026 unfolds, these stocks will serve as barometers for the resilience of innovation-driven sectors in a shifting economic landscape.