--- title: "Lilly lands at 19.9% of TRex Bio, 34,635 shares short of the 20% line" description: "A Schedule 13D filed on October 16 shows Eli Lilly holding 19.9% of TRex Bio a week after the biotech's Nasdaq debut, $12.3 million of it bought inside the IPO itself. The stake stops just under 20%, the mark where US accounting presumes significant influence and the SEC's quiet short form goes away." publisher: "The Inference" section: "Markets" published: 2026-10-17T19:04:38.421Z modified: 2026-10-17T19:04:38.421Z canonical: https://theinference.org/article/lilly-lands-at-19-9-of-trex-bio-34-635-shares-short-of-the-20-line language: en keywords: "Biotech, IPO, Pharma, SEC Filings, Ownership, Markets" --- # Lilly lands at 19.9% of TRex Bio, 34,635 shares short of the 20% line > A Schedule 13D filed on October 16 shows Eli Lilly holding 19.9% of TRex Bio a week after the biotech's Nasdaq debut, $12.3 million of it bought inside the IPO itself. The stake stops just under 20%, the mark where US accounting presumes significant influence and the SEC's quiet short form goes away. On October 16, 2026, [Eli Lilly](https://theinference.org/markets/companies/eli-lilly) (NYSE: LLY) [filed a Schedule 13D](https://www.sec.gov/Archives/edgar/data/59478/000005947826000095/0000059478-26-000095-index.htm), the SEC's long-form disclosure for a holder above 5%, on TRex Bio (Nasdaq: TRXB), the South San Francisco company that went public a week earlier. Lilly reports 5,480,872 shares, 19.9% of the 27,577,535 outstanding as of October 13, 2026 [3]. Preferred stock from earlier funding rounds converted into 4,605,872 of them; the other 875,000 Lilly bought inside the IPO itself, at $14.00 a share, for about $12.3 million [3]. TRex Bio maps regulatory T cells, the immune system's brake pedals, in human tissue; [its October 8, 2026, offering priced 8,333,334 shares at $14.00](https://www.sec.gov/Archives/edgar/data/2139097/000119312526419203/project_dino_-_424b4.htm), the bottom of the range, and [the stock closed flat on debut](https://finance.yahoo.com/healthcare/articles/play-trxb-stock-trex-bio-152941494.html) [1][2]. The next-largest bloc in the prospectus, entities of SV Health Investors, holds 14.1% [1]. *Chart: **Lilly and SV Health together hold about a third of TRex Bio** Pie chart of TRex Bio's ownership after the October 2026 IPO: Lilly 19.9%, SV Health Investors 14.1%, public float 30.2%, other pre-IPO holders 35.8%* *Lilly and SV Health per the Schedule 13D and the prospectus; public float as the 8,333,334 IPO shares (30.2%); the rest as the balance of the 27,577,535 shares outstanding as of October 13, 2026. Sources: SEC filings. [1][3]* ## 34,635 shares, two rulebooks Twenty percent of TRex Bio's stock is 5,515,507 shares [3]. Lilly holds 34,635 fewer [3]. [Accounting presumes significant influence at 20% of voting shares](https://en.wikipedia.org/wiki/Equity_method), which brings equity-method accounting and a slice of the target's profits into the holder's income [4][5]. Below that line, a stake is normally carried at cost or fair value, unless the holder's actual influence is clear [4][5]. The securities rules draw the same mark: [the short-form 13G is reserved for passive holders](https://www.ecfr.gov/current/title-17/part-240/section-240.13d-1) and is unavailable at 20% or more [6]. The cap was printed before the first trade. TRex Bio's prospectus, dated October 8, 2026, said Lilly's IPO purchases would keep its combined holding from exceeding 19.9% of the shares outstanding after the offering [1]. ## Lilly files the active form while its employee sits on the board Lilly took the 13D, due within five business days and demanding a statement of purpose [6]. It told the SEC it expects discussions with TRex Bio's directors and management covering "operational, financial and strategic initiatives," while stating it has no specific plan or proposal [3]. Julie Gilmore, a Lilly vice president who runs its Gateway Labs unit, has sat on TRex Bio's board since December 2024, and the filing notes Lilly holds no contractual right to the seat [1][3]. The ties are older than the listing. Chief executive M. Johnston Erwin spent more than 35 years at Lilly, and TRB-051, the drug candidate licensed to Lilly in January 2023 for $55 million upfront plus a $15 million milestone, is set to enter a Phase 2a lupus trial this half [1]. *Chart: **Lilly's stake stops 34,635 shares short of the 20% line** Bar chart of the blocks making up Lilly's TRex Bio holding, with the total just below a 20% threshold line* *Share counts per Lilly's Schedule 13D, filed October 16, 2026. The 20% line is 20% of the 27,577,535 shares outstanding as of October 13, 2026. [3]* ## Locked to April 6, 2027, read again on October 29 Lilly cannot sell for 180 days from October 8, 2026, without consent from lead underwriters [J.P. Morgan](https://theinference.org/markets/companies/jpmorgan-chase) and [Evercore](https://theinference.org/markets/companies/evercore), a window that runs to April 6, 2027 [1][3]. The filing describes the holding as bought for investment and reserves every option, buying more or selling out [3]. The IPO left 8,333,334 shares in public hands; substantially all the rest, SV Health's bloc included, is locked up until April alongside Lilly's [1][3]. If TRex Bio is ever acquired, the likeliest buyer is its largest holder, which already runs the licensed drug and employs a board member [1][3]. [Lilly reports third-quarter results on October 29, 2026](https://www.biospace.com/press-releases/lilly-confirms-date-and-conference-call-for-third-quarter-2026-financial-results-announcement) [7]. The readings after that are any amendment to the 13D and the lock-up's expiry. Lilly sits 34,635 shares below the line where TRex Bio's profits and losses would start flowing into its own income statement [3][4]. ## Takeaway Eli Lilly drew its own line at 19.9% of TRex Bio, a share short of the 20% mark that flips on equity-method accounting and forces the 13D's longer shadow; the board seat, the old license and the lock-up say the relationship is anything but passive. ## Sources 1. [SEC EDGAR, TRex Bio, Inc. prospectus (Rule 424(b)(4)), dated 8 October 2026](https://www.sec.gov/Archives/edgar/data/2139097/000119312526419203/project_dino_-_424b4.htm) 2. [Barchart via Yahoo Finance, "How to Play TRXB Stock After the TRex Bio IPO", 13 October 2026](https://finance.yahoo.com/healthcare/articles/play-trxb-stock-trex-bio-152941494.html) 3. [SEC EDGAR, Eli Lilly & Co Schedule 13D on TRex Bio, Inc., filed 16 October 2026](https://www.sec.gov/Archives/edgar/data/59478/000005947826000095/0000059478-26-000095-index.htm) 4. [Wikipedia, "Equity method", accessed 17 October 2026](https://en.wikipedia.org/wiki/Equity_method) 5. [Corporate Finance Institute, "Equity Method", accessed 17 October 2026](https://corporatefinanceinstitute.com/resources/accounting/equity-method/) 6. [eCFR, 17 CFR 240.13d-1, Filing of Schedules 13D and 13G, current as of 15 October 2026](https://www.ecfr.gov/current/title-17/part-240/section-240.13d-1) 7. [BioSpace, "Lilly confirms date and conference call for third-quarter 2026 financial results announcement", 15 October 2026](https://www.biospace.com/press-releases/lilly-confirms-date-and-conference-call-for-third-quarter-2026-financial-results-announcement) --- Lilly lands at 19.9% of TRex Bio, 34,635 shares short of the 20% line — The Inference. Canonical: https://theinference.org/article/lilly-lands-at-19-9-of-trex-bio-34-635-shares-short-of-the-20-line