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.
Vincent Jiang · 3 min read
On October 16, 2026, Eli Lilly+0.33% — Eli Lilly, up 0.33 percent today (NYSE: LLY) filed a Schedule 13D, 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, the bottom of the range, and the stock closed flat on debut 12. The next-largest bloc in the prospectus, entities of SV Health Investors, holds 14.1% 1.
Lilly and SV Health together hold about a third of TRex Bio
- Eli Lilly19.9%19.9%
- SV Health Investors14.1%14.1%
- Public float (IPO shares)30.2%30.2%
- Other pre-IPO holders35.8%35.8%
Data
| Slice | Value | Share |
|---|---|---|
| Eli Lilly | 19.9% | 19.9% |
| SV Health Investors | 14.1% | 14.1% |
| Public float (IPO shares) | 30.2% | 30.2% |
| Other pre-IPO holders | 35.8% | 35.8% |
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, which brings equity-method accounting and a slice of the target's profits into the holder's income 45. Below that line, a stake is normally carried at cost or fair value, unless the holder's actual influence is clear 45. The securities rules draw the same mark: the short-form 13G is reserved for passive holders 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 13.
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.
Lilly's stake stops 34,635 shares short of the 20% line
Data
| Value | |
|---|---|
| Series A preferred, converted | 2,510,411 |
| Series B preferred, converted | 2,095,461 |
| Bought in the IPO at $14 | 875,000 |
| Lilly's total holding | 5,480,872 |
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+1.11% — J.P. Morgan, up 1.11 percent today and Evercore−0.99% — Evercore, down 0.99 percent today, a window that runs to April 6, 2027 13. 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 13. If TRex Bio is ever acquired, the likeliest buyer is its largest holder, which already runs the licensed drug and employs a board member 13.
Lilly reports third-quarter results on October 29, 2026 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 34.
Deepdive
AI-generated from this story and its cited sources. Not investment advice.
