Lightmatter is private with no S-1 on file. The $4.4bn Series D, the Passage M1000 photonic interposer, the OCP standards role, and the listed proxies — $GFS, $AMKR, $QCOM, $CLS, $KEYS.
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Lightmatter is private. There is no Lightmatter ticker, no IPO, and as of August 2026 no S-1 on file with the SEC. Several aggregator sites claim otherwise; a direct EDGAR search for Lightmatter registration statements returns no matching companies. What exists is a $4.4bn-valuation photonics company that leads the industry group writing the co-packaged optics standard, and a set of listed suppliers whose businesses move when Lightmatter's does.
👉 See the listed supply chain: the Photonics / CPO basket and the Silicon Photonics & Optical Interconnects trend on Macroplane.
Three things drive the search volume, and none of them is a listed security.
The Series D. In October 2024 Lightmatter raised $400M at a $4.4bn valuation, quadrupling its previous mark and taking total funding to about $850M. The round was led by investors advised by T. Rowe Price, with Fidelity and Google Ventures participating. Crossover funds like T. Rowe and Fidelity typically enter a round when an IPO is in view, and CEO Nick Harris described it at the time as probably the company's last private round. That is the origin of most of the IPO speculation.
The secondary market. Lightmatter shares change hands on private secondary platforms, which publish indicative prices that look like stock quotes and get indexed as if they were. Nasdaq Private Market marked roughly $62 per share in May 2026 and roughly $84 in August 2026. Those are accredited-investor secondary marks, not a public price, and the spread between platforms is wide.
The OCP announcement. On 13 August 2026 Lightmatter led the formal launch of "Open Silicon Photonics for AI Systems" as an official Open Compute Project workstream, a 19-company effort with a roughly 300-page architectural blueprint and first specifications targeted for Q4 2026. A private company chairing the standards body for an entire architecture is unusual, and it put Lightmatter in front of a much wider audience.
The product is Passage, and the distinguishing choice is that Lightmatter puts the photonics in the interposer rather than in a separate optical engine beside the chip.
The Passage M1000 is a 3D photonic superchip: a multi-reticle active photonic interposer larger than 4,000 mm², built as an eight-tile 3D interposer with an integrated programmable waveguide network. It carries 1,024 electrical SerDes, supports 256 attached fibres, and claims 114 Tbps of total optical bandwidth. Compute dies sit on top of it, and light moves between them through the substrate they are mounted on.
That is architecturally different from what Broadcom and NVIDIA ship. Their co-packaged optics put optical engines around the edge of a switch ASIC package. Lightmatter's approach makes the whole substrate the optical fabric, which is aimed less at switch ports and more at connecting many accelerators into a single large domain.
Whether that is better is genuinely unsettled. It is more ambitious, less proven at volume, and it requires a reticle-stitched active interposer, which is a hard thing to yield.
This is the practical answer to the search. Lightmatter's platform has named manufacturing and design partners, all of them public.
| Company | Ticker | Role in Lightmatter's stack |
|---|---|---|
| GlobalFoundries | $GFS | GF Fotonix is the silicon photonics platform the M1000 is built on |
| Amkor | $AMKR | Advanced packaging partner for M1000 production readiness |
| Qualcomm | $QCOM | 112G PAM4 optical SerDes chiplet paired with the Passage engine |
| Celestica | $CLS | OCP workstream member; took a hyperscaler CPO switch award ramping 2027 |
| Keysight | $KEYS | OCP founding member; CPO test and validation |
| Flex | $FLEX | OCP workstream member, system integration |
$GFS is the most direct read. Fotonix is GlobalFoundries' differentiated platform in a business where it cannot compete with TSMC on leading-edge logic, and Lightmatter is its highest-profile design win. If Passage ramps, it ramps on GlobalFoundries wafers.
The rest of the OCP membership list is a useful map of who expects to build this: Dell ($DELL), Foxconn Interconnect Technology ($6088.HK), Global Unichip ($3443.TW), Hyve Solutions and Quanta Cloud Technology ($2382.TW) alongside those above.
Nothing in the public record indicates a filing is imminent. The things that would change that:
Treat any pre-IPO allocation offer with the scepticism the secondary-price spread deserves. The gap between the Nasdaq Private Market mark and other platform quotes in August 2026 was wide enough to matter, and secondary buyers have no information rights.
Not on a public exchange. Lightmatter is private, has no ticker, and has no registration statement on file with the SEC as of August 2026. Accredited investors can sometimes buy shares on private secondary platforms, at prices that vary widely between venues and carry no information rights.
There is no confirmed IPO. The October 2024 Series D was led by crossover investors advised by T. Rowe Price with Fidelity participating, which often precedes a listing, and the CEO described it as likely the last private round. No S-1 has been filed. Some aggregator sites incorrectly state that Lightmatter has already completed an IPO.
The last primary round, a $400M Series D in October 2024, valued the company at $4.4bn. Private secondary marks in 2026 imply a higher number, but secondary prices on accredited-investor platforms are indicative and inconsistent between venues.
Lightmatter builds photonic interconnect for AI infrastructure. Its Passage M1000 is a 3D photonic superchip: a multi-reticle active photonic interposer larger than 4,000 mm² with 1,024 electrical SerDes, 256 fibre attachments and a claimed 114 Tbps of optical bandwidth, built on GlobalFoundries' Fotonix platform.
GlobalFoundries ($GFS) manufactures the photonics platform, Amkor ($AMKR) provides advanced packaging, and Qualcomm ($QCOM) supplies the optical SerDes chiplet. Celestica ($CLS), Keysight ($KEYS) and Flex ($FLEX) sit in the same OCP silicon photonics workstream. The broader Photonics / CPO basket covers the supply chain.
This is research and education, not financial advice. Private-market securities carry liquidity and information risks that listed equities do not. Do your own work.
Not on a public exchange. Lightmatter is private, has no ticker, and has no registration statement on file with the SEC as of August 2026. Accredited investors can sometimes buy shares on private secondary platforms, at prices that vary widely between venues and carry no information rights.
There is no confirmed IPO. The October 2024 Series D was led by crossover investors advised by T. Rowe Price with Fidelity participating, which often precedes a listing, and the CEO described it as likely the last private round. No S-1 has been filed. Some aggregator sites incorrectly state that Lightmatter has already completed an IPO.
The last primary round, a $400M Series D in October 2024, valued the company at $4.4bn. Private secondary marks in 2026 imply a higher number, but secondary prices on accredited-investor platforms are indicative and inconsistent between venues.
Lightmatter builds photonic interconnect for AI infrastructure. Its Passage M1000 is a 3D photonic superchip: a multi-reticle active photonic interposer larger than 4,000 mm² with 1,024 electrical SerDes, 256 fibre attachments and a claimed 114 Tbps of optical bandwidth, built on GlobalFoundries' Fotonix platform.
GlobalFoundries ($GFS) manufactures the photonics platform, Amkor ($AMKR) provides advanced packaging, and Qualcomm ($QCOM) supplies the optical SerDes chiplet. Celestica ($CLS), Keysight ($KEYS) and Flex ($FLEX) sit in the same OCP silicon photonics workstream. The broader Photonics / CPO basket covers the supply chain. This is research and education, not financial advice. Private-market securities carry liquidity and information risks that listed equities do not. Do your own work.