Culper Research Short NexGen Energy: You Can't Have Your Yellowcake and Eat It Too
On February 6, 2026, Culper Research published a short report on NexGen Energy Ltd. (NYSE: NXE / TSX: NXE), developer of the Rook I project (the 'Arrow' deposit) — a basement-hosted uranium deposit in Saskatchewan's Athabasca basin which the company calls 'the world's most strategic uranium asset.' Culper alleges that Rook I's claimed C$6.3 billion NPV is overstated by 43% to 62%, that NexGen's claimed 29.7 million lbs. peak annual uranium production is impossible to achieve, and that NexGen is 'ultimately an insider enrichment scheme with substantial downside.'
Epistemic note. Culper Research is a short seller that discloses a financial interest in the decline of NXE stock. Its allegations — including the NPV-overstatement claim, the production-feasibility critique, the assay-grade skepticism, and the insider-enrichment characterization — are the opinions of a third party with a disclosed short position. None of this has been independently verified by The Forensic Ledger, adjudicated by a regulator or court, or admitted by NexGen Energy.
'They're not mining uranium; they're mining the stock market'
The report opens with a quote from a 40-year uranium industry veteran: 'Leigh is a finance guy – the spreadsheets are all going to be tweaked to come up with the best NPV… They're driven by spreadsheets more so than actual production. When it comes to putting the mine plan on paper though, it's just on paper. All this work on making the NPV look as attractive as possible… That's why they talk about these 30 million lbs. all along. They're not mining uranium; they're mining the stock market. You can just get investors excited without ever going into production.'
A decade of drilling that found almost nothing new
Culper states that Rook I's NPV is underpinned by ultra-high-grade pods discovered a decade ago, by a single contractor, analyzed at a single laboratory, with no twin hole drilling or secondary lab analysis. The report states that from Summer 2015 to Summer 2016, NexGen discovered 22 ultra-high-grade pods at greater than 30% uranium (a 13% hit rate), with peak assays reaching 80.5%. In the decade since, the report states, NexGen has drilled 299 additional holes and produced just 3 pods grading greater than 30% (a 1% hit rate) at peak mineralization of 33.78%. Culper poses the question: either NexGen found virtually all of Arrow's best material a decade ago, or early assays overstate actual grades.
The original discovery team left
The report states that despite uncovering supposedly the greatest uranium asset on the planet, NexGen's original discovery team largely left the company — many for junior miners. Culper states that VP of Exploration Garrett Ainsworth, who led the Arrow discoveries, left in 2018 for a ~$50 million junior miner; NexGen's General Counsel resigned the same day; Chief Project Officer Anthony George — whom NexGen said would take Rook I 'through to production' — stepped down in 2022 and left entirely in 2024; and that exploration geologists, SVPs, and project managers have similarly left for microcap companies. The report also states that NexGen has cycled through seven CFOs since 2012.
A2-HG: the single zone Rook I 'lives and dies' on
Culper states that NexGen now portrays Arrow as a thick, continuously mineralized orebody centered on A2-HG — a single high-grade zone at 16.65% Measured grade that the report says carries 68% of total metal. To meet the company's 29.7M lbs./year production claims, the report states, NexGen plans to simultaneously mine multiple stopes, blend high-grade A2-HG material with low-grade ore underground to stay below a 5% maximum mill feed grade, all while backfilling mined-out areas via what the company calls a 'novel' underground tailings management facility. Culper states it estimates A2-HG must continually deliver mill feed grades of approximately 10.85%, implying 16.39% pre-dilution grades — against A2-HG Measured resources grading 16.65% after density weighting and a 0.25% cut-off. The mine plan, the report argues, already has little to no room for error.
'A complex dance' that pushes mine life out
The report states that, independent of Culper's own concerns, multiple decades-long uranium operators it spoke with suggested that NexGen's plan 'appears driven by optimizing Rook I's NPV on paper, rather than real-world operational feasibility.' It quotes one: 'the mining plan is created more by creating the most attractive NPV rather than what actually makes sense. It'd make way more sense to do 10 to 15 million pounds.' Another: 'they set up such a high level at first that it's so much pressure.' Per another, this 'complex dance' will push the mine life out, forcing NPV lower.
Un-nesting the assay data
Culper states that NexGen has consistently reported headline assay intervals that portray Arrow as a thick, continuously mineralized orebody. The report gives the example of hole AR-16-63c2, which NexGen reported as intersecting 42 meters at 15.2%. When Culper un-nests the full assay data, the report states, it finds two separate pods of just 4.5 and 7 meters — suggesting, in Culper's characterization, that the headline interval overstates the continuity and thickness of the mineralization.
What would falsify this thesis
Falsification would look like: NexGen delivering twin-hole drilling and secondary lab analysis that confirms the original ultra-high-grade assays; A2-HG demonstrating the thickness and continuity the mine plan requires; the company achieving, or credibly progressing toward, production at or near 29.7M lbs./year; and the 'novel' underground tailings management facility proving operationally feasible. Corroborating developments would include independent verification (or refutation) of the Arrow assays, a downward revision of the Rook I NPV or production profile, further executive departures, regulatory or permitting delays, or the company raising dilutive capital on terms that suggest the project is less economic than portrayed.
Culper Research's disclosed position
Culper Research disclosed that it, along with its members, partners, affiliates, employees, consultants, clients, and/or investors, has a position in NXE securities, that it is likely to transact in the securities immediately following publication, and that it may be long, short, or neutral at any time thereafter regardless of its initial recommendation.
Source
⚖️ Editorial Disclaimer
This article summarizes with citation a research report already published by Culper Research. The Forensic Ledger is an independent newsroom and archive; it is not the author of the underlying allegations and does not adopt them as established fact. All figures and characterizations attributed to the report — including the NPV-overstatement claim, the production-feasibility critique, the assay-grade skepticism, the executive-departure narrative, and the insider-enrichment characterization — are the opinions of a third party (Culper Research) that discloses a financial interest in the decline of the covered security. These claims have not been independently verified by The Forensic Ledger, have not been adjudicated by any court or regulator, and may be denied or disputed by NexGen Energy. This article is published for informational and journalistic purposes only, is not investment advice, and is not a recommendation to buy, sell, or hold any security.
Original reporting by Culper Research. This article is desk analysis prepared by The Forensic Ledger from publicly available sources, summarized with citation to the original.
Not investment advice. This is original reporting and analysis prepared by The Forensic Ledger from publicly available data. Nothing here is a recommendation to buy, sell, or hold any security. Always consult the original source and a licensed professional. See our full disclaimer and source-citation policy.
