How to invest in Lightmatter stock pre-IPO

AI computing has sharply increased demand for both electricity and the physical space needed to build large data centers. U.S. data center electricity use is projected to reach 325 to 580 TWh by 2028, up from 176 TWh in 2023, according to the Department of Energy.⁴ Existing facilities also struggle to keep pace with AI workloads, since processors such as GPUs need ultra-fast connections between them to reach their potential.⁵

Lightmatter is working on a response to these constraints. Rather than relying on electricity-based links that move data through copper wires, Lightmatter uses silicon photonics. That means data from processors travels as light, or photonics, along pathways etched in silicon.

One argument for this change is that copper wires heat up as data passes through them, adding to a data center's electricity demands, while silicon photonics stay cool. Light also enables higher data transmission bandwidth and less signal loss over long distances, according to Lightmatter.⁶ The result is faster, more energy-efficient data transmission that can address cost, performance and sustainability, the company explains.⁶

That efficiency could be particularly important in terms of the connections between processors, where AI models move enormous volumes of data during training and inference. By replacing electrical links with optical ones, Lightmatter aims to reduce the bottlenecks that limit how many chips can work together on a single workload.⁷

Lightmatter builds solutions that fit into existing data centers, such as by using co-packaged optics (CPO) and near-packaged optics (NPO),⁸ as well as integrated computing products that support AI workloads as an alternative to traditional processor chips.⁹ The technology remains in relatively early stages, but the company has grown substantially since its founding in 2017. Its October 2024 round valued Lightmatter at $4.4 billion, and comments from its leadership suggest a public listing could be in the pipeline.³

For now, though, Lightmatter remains a private company, meaning its shares are not publicly tradeable through traditional brokerages. Instead, interested accredited investors may be able to invest in Lightmatter stock pre-IPO through a private marketplace such as Forge, subject to share availability, investor eligibility and other applicable requirements. Non-accredited investors may also be able to gain indirect exposure through other assets, as this guide explains.

Lightmatter: company background

Lightmatter, based in Silicon Valley, was founded in 2017 by three MIT alumni — Nicholas Harris Ph.D, Darius Bunandar Ph.D, and Thomas Graham.¹⁰ The company started its development by winning the 2017 MIT $100K Entrepreneurship Competition with a prototype of its optical chip,¹¹ and it also took the Open track grand prize at the Harvard Innovation Labs President's Innovation Challenge that year.¹²

At MIT, Harris¹⁵ and Bunandar¹³ completed doctorates related to quantum photonics. Graham earned his MBA at MIT and holds a master's in computer science from Columbia University.¹³

Lightmatter's main product lines are Passage (a photonics interconnect platform), and Guide (a software-defined light engine).¹³

The founding team has steered the company from an academic prototype toward commercial products. For example, in June 2026, Lightmatter announced a partnership with Nvidia as part of the NVIDIA NVLink Fusion ecosystem, enabling customers with semi-custom XPUs to use Lightmatter's optical interconnect technologies to connect their chips directly with Nvidia's switch silicon.⁶ In 2024, Lightmatter also appointed Simona Jankowski, a former Nvidia vice president of investor relations and strategic finance, as its chief financial officer, which potentially suggests a step toward more commercialization and a possible IPO path.¹⁴

Lightmatter stock history and funding history

Lightmatter has raised more than $800 million across several primary funding rounds since its founding. Its valuation climbed from roughly $32 million at its first institutional raise to $4.4 billion in 2024, tracking its progress from prototype to commercial products.¹

Forge Data as of 09/22/2026

The company started with a Series A round in 2018 that brought in $11.10 million at a $2.75 stock price and a $31.71 million valuation, backed by Matrix Partners and Spark Capital.¹ The following year, a Series A extension raised $22.29 million at a $5.90 stock price and a $92.15 million valuation, with investment from GV (Google Ventures) and Matrix Partners.¹

In 2021, Lightmatter raised $80 million for its Series B at a stock price as high as $8.77 and a $251.03 million valuation.¹ Viking Global Investors led the round, joined by Hewlett Packard Enterprise, Lockheed Martin and SIP Global Partners.¹

Two years later, Lightmatter raised the first phase of its Series C, bringing in $153.28 million from several repeat investors as well as Fidelity. That round lifted its stock price to $16.46 and more than doubled its valuation to $637.5 million. At the end of 2023, a second Series C phase raised $155 million, taking the stock price to $26.00 and the valuation to $1.2 billion, with investment again from GV and Viking Global Investors.¹

Most recently, in October 2024, Lightmatter raised $400 million for its Series D. The round took its valuation to $4.4 billion and its stock price as high as $80.23,¹ with T. Rowe Price leading.¹

Since then, Lightmatter's Forge Price has climbed to $84.48 at a $4.63 billion valuation, as of August 20, 2026.² That marks an 18% increase from its October 2024 Series D valuation. Lightmatter's Forge Price did drop down to a low of $48.00, implying a $2.63 billion valuation in mid-2025, but it has since recovered, particularly with a sharp move up in May 2026.²

Forge Data as of 09/22/2026

Forge Price is a derived data point that reflects the up-to-date price performance of venture-backed, late-stage companies, and is calculated based on a proprietary model incorporating pricing inputs from primary funding round information, secondary market transactions and indications of interest (IOIs) on Forge.

Lightmatter IPO outlook

Lightmatter has not announced an IPO date and remains a private company. Co-founder and CEO Nick Harris told Reuters that the October 2024 round would probably be the company's "last private funding round" before going public, though no concrete steps toward a public listing have followed.³

Factors that could support an eventual listing include Lightmatter's technology developments, commercial traction and overall trends in the AI and data center industries. However, the company has not confirmed a filing plan or financial thresholds, and market conditions could shape any decision to go public.

As such, any IPO timeline remains uncertain. Investors weighing pre-IPO exposure should treat IPO timing as speculative and base decisions on publicly available information rather than on expectations of a specific listing date. You can check Lightmatter's IPO stock page on Forge for updates.

How to invest in Lightmatter stock

Lightmatter has not gone public, and as such, its shares are not available to trade via traditional brokerages.

Instead, accredited investors may be able to access shares of some pre-IPO companies like Lightmatter through secondary market transactions on private marketplaces like Forge, through which existing shareholders such as employees or early investors may sell their holdings. An accredited investor is a person or entity that meets income or net-worth thresholds, or professional criteria, as set by the SEC.¹⁷

However, private market access can come with constraints. Share availability is not guaranteed, and companies often impose transfer restrictions, including a Right of First Refusal (ROFR) that lets the company or existing investors buy shares before an outside buyer can when an existing shareholder tries to sell. Private company shares are also typically illiquid, especially compared to public market securities, and valuations can be uncertain.

To learn more about pre-IPO opportunities, explore our buyer's guide to investing in private market shares or our comprehensive pre-IPO investing guide. Eligible investors can also create a free account on Forge to explore available private market investment opportunities.

Potential indirect exposure to Lightmatter for non-accredited investors

Direct pre-IPO investment in Lightmatter is generally limited to accredited investors. non-accredited investors may be able to gain indirect or correlated exposure to Lightmatter through some publicly available options that track related trends.

For example, retail investors might choose to invest in publicly traded photonics and interconnect companies that compete somewhat with Lightmatter, or they might invest in semiconductor companies that might partner with Lightmatter or be exposed to similar AI and data center trends. Another route could be to invest in broader technology funds, spanning areas such as AI, cloud computing, robotics, and quantum computing. The degree of correlation with Lightmatter depends on the specific underlying investments, so investors might decide between funds that track similar industries or ones that provide more diversified exposure.

Ultimately, though, these options provide thematic or indirect exposure only. None represents direct ownership of or equivalent economic exposure to Lightmatter, and performance may vary based on the specific operations and market factors affecting the underlying companies retail investors might choose.

How to analyze Lightmatter stock

Private companies generally do not face the same disclosure requirements as public companies, which can make analyzing Lightmatter stock challenging. As an early-stage company still developing its products and building out its commercialization, Lightmatter has disclosed little financial information.

According to third-party estimates from Latka, Lightmatter had $116 million in revenue in 2024, up from $49.9 million the year before.¹⁸ Figures like these, combined with the company's valuation across its funding rounds and its current Forge Price, can help investors compare Lightmatter with similar private companies listed on Forge's marketplace.

Reviewing how other technology companies trade on Forge might help investors gauge what they deem to be a reasonable valuation for Lightmatter, and there may be parallels to draw with public market peers. Even so, private market stocks are generally more opaque than public ones, so analyzing Lightmatter's valuation involves more subjectivity than assessing a public company.

Potential risks of investing in pre-IPO Lightmatter stock

Investing in a private, pre-IPO company like Lightmatter involves some risks that can affect company performance, valuation, liquidity and potential outcomes. The factors below provide context, and investors should conduct their own due diligence before making any decision.

• Company-specific risks. Its silicon photonics products are still maturing, and adoption at scale is not guaranteed, which could affect growth, valuation or IPO prospects.
• Competitive pressures. Lightmatter competes with established chip and interconnect companies, and market dynamics could shift in favor of alternative technologies.
• Execution and regulatory challenges. Operational missteps, supply constraints or regulatory changes could slow the company's progress.
• Valuation considerations. Private valuations can move sharply between funding rounds and may not align with investor expectations.
• Private market investing risks. Shares are generally illiquid compared to public market shares, and shares may be subject to transfer restrictions, limited disclosure and share-availability constraints.
• Potential loss of capital. As with any investment, and especially with speculative pre-IPO holdings, investors could lose some or all of their capital.

Get started investing in Lightmatter on Forge

If you are interested in investing in Lightmatter before a potential IPO if/when shares become available, eligible investors can open a free Forge account. Once your account is active and your accreditation is verified, you may gain access to real-time private market data, context-rich insights and a marketplace built for self-directed investors.

Not sure where to begin? You can read our buyer's guide to investing in private market shares. And if questions come up along the way, Forge's experienced specialists are available to support you.