Nebius' Reflection AI Deal Adds $1 Billion, But Insider Sales and Meta Jitters Keep Investors on Edge

Nebius Group shares fall 5.35% amid insider selling spree and rising short interest, despite a $1B+ deal with AI startup Reflection and $50B backlog.

Nebius Group's stock slid 5.35% to €175.00 on Tuesday, extending a pullback that has seen the shares tumble 32.95% from the 52-week high of €261.00 set on June 22. The move came despite the AI infrastructure company announcing a blockbuster computing contract with startup Reflection AI worth more than $1 billion through 2029, including access to Nvidia's latest GB300 chips. The divergence between the growing order book and a nervous market has rarely been starker.

The Reflection deal underscores Nebius' role as a prime beneficiary of the AI arms race. Founded in 2024 by former Google DeepMind researchers Misha Laskin and Ioannis Antonoglou, Reflection develops open-source AI models as an alternative to offerings from OpenAI and Anthropic. It closed a roughly $2 billion fundraise in late 2025 at an $8 billion valuation, backed by Nvidia, Sequoia and Lightspeed, and is now reported to be negotiating a $2.5 billion round at a $25 billion valuation. The Nebius contract builds on a separate agreement with SpaceX signed in June, which provides Reflection with around $150 million in monthly computing capacity through 2029.

For Nebius, the Reflection pact is another brick in a wall of multi-billion-dollar contracts. In March, the company sealed a $27 billion five-year deal with Meta Platforms that begins in 2027. A $17.4 billion contract with Microsoft followed, and Nvidia itself took a $2 billion equity stake in March. Total contracted backlog now stands at roughly $50 billion, according to reports. The company, carved out of Yandex in 2024, is investing heavily: its 2026 capital expenditure budget runs $20 to $25 billion, and it targets 4 gigawatts of computing capacity by year-end, including a new 1.2-gigawatt site in Pennsylvania. Cash reserves exceed $9 billion.

Yet the operational momentum has done little to calm investors fretting over insider selling and the possibility that a key customer may become a competitor. Regulatory filings show that CEO Arkadiy Volozh sold 46,627 shares at $235.45 each, collecting roughly $10.98 million. CTO Danila Shtan and infrastructure chief Andrey Korolenko also disposed of shares worth $3.99 million and $7.97 million respectively. Nebius stressed that Volozh's transaction was automatic, executed to cover tax obligations on vesting restricted share units — not a discretionary move. A separate SEC filing confirms the mechanism was pre-arranged. Still, over the past 90 days, insiders have sold $134 million worth of stock across 37 transactions, with a net sales balance of $4.87 million. In the last twelve months, there have been 17 insider sales and not a single purchase. Elena Bunina and Korolenko alone shed more than 626,000 shares in the last three months, and not all of those trades are flagged as automatic tax sales.

The selling spree has attracted short sellers. Short interest swelled from 20.13% of the float in mid-June to 28.55% currently, with the number of shares borrowed rising from 50.93 million to 61.01 million. The bearish positioning reflects broader anxiety about the sustainability of AI infrastructure demand. Reports that Meta is exploring an entry into the AI computing business have stoked fears that a customer could turn rival. That prospect is particularly unsettling given Meta's $27 billion commitment to Nebius. If the social media giant builds its own capacity, the need for outside providers could shrink.

Not everyone is convinced the Meta threat is real. Analysts at SemiAnalysis argued that the market may be overreacting, and that Meta's growing hunger for compute could actually create more opportunities for hyperscalers like Nebius. A Seeking Alpha analyst reiterated a buy recommendation, noting the stock trades at 16.6 times expected enterprise-value-to-sales. Nine analysts tracked by one poll set an average price target of $252.86, while another poll places the consensus at $236.83. The broader rating stands at "Moderate Buy," down from "Strong Buy" three months ago.

Technically, the stock shows signs of exhaustion. It now trades 11.65% below its 50-day moving average of €198.09, though it remains 47.52% above the 200-day average of €118.63. The 14-day relative strength index sits at 41.0, indicating weak near-term momentum but not oversold territory. Annualized 30-day volatility is an extraordinary 100.38%. Year-to-date, the shares are still up 128.76%, and over twelve months they have soared 292.38% — gains that may themselves be a reason for profit-taking as the market weighs an increasingly complex narrative.