Lightmatter is a private company and has not filed a registration statement for an IPO. The photonic-computing company closed a $400 million Series D on October 16, 2024, led by new investor T. Rowe Price with participation from GV and Fidelity Management and Research Co., at a $4.4 billion valuation, nearly quadrupling its prior $1.2 billion mark from roughly ten months earlier. Co-founder and CEO Nick Harris told Reuters at the time, 'This is probably our last private funding round,' an indirect signal about direction, not a stated date. As of the latest site review, no newer primary round has been publicly reported, and Lightmatter has not filed with the SEC. Separately, PitchBook's VC Exit Predictor, cited by Morningstar in July 2026, put Lightmatter's IPO probability at 94% alongside a broader wave of chip-startup listings that the same report said could face delays. Track SEC EDGAR and Lightmatter's own newsroom directly, not rumors or secondary-market chatter.
segmara.com publishes educational private-market context and can route limited interest into account-based private follow-up. Public pages do not create an offer, allocation, payment instruction, investment advice, or issuer-affiliated workflow.
Key points
A CEO's own words point toward a listing
Lightmatter, a Boston-based photonic-computing company founded in 2017 by CEO Nick Harris and colleagues, closed a $400 million Series D on October 16, 2024, according to Crunchbase News. New investor T. Rowe Price led the round, with existing backers GV and Fidelity Management and Research Co. also participating, at a $4.4 billion valuation, nearly four times the $1.2 billion valuation the company held roughly ten months earlier after a $155 million round led by GV.
Harris told Reuters at the time, 'This is probably our last private funding round,' one of the more direct forward-looking statements from any founder tracked on this site. That is a stated expectation about direction, not a committed date, and Lightmatter has taken no further public step toward a listing since.
What an outside model says, and does not say
PitchBook's VC Exit Predictor, republished by Morningstar in July 2026 as part of a broader look at semiconductor-startup IPO plans, assigns Lightmatter a 94% IPO probability, based on the company's $820 million in disclosed capital raised and $4.5 billion last-known valuation, both figures broadly consistent with the October 2024 round.
That is a statistical estimate built from funding and market data, not a Lightmatter announcement. The same Morningstar report described a mid-2026 semiconductor-stock selloff, driven partly by a record-setting Shanghai IPO from Chinese chipmaker CXMT, as a headwind that could push chip-startup listings, including ones with high predicted probabilities, into late 2026 or 2027 rather than cancel them outright.
What would actually change the picture
Nothing here substitutes for a filing. A public S-1 on SEC EDGAR, or a specific date or underwriter announcement from Lightmatter leadership, would be the first verifiable signal that an actual IPO process has begun. Neither exists as of the latest site review.
Given Harris's own 2024 comment about the Series D likely being the company's last private round, and PitchBook's high probability score, Lightmatter looks directionally closer to a listing than many private companies. Directional confidence is still not a date, and any specific 'Lightmatter IPO date' circulating online remains speculation until the company or a filing says otherwise.
Private-share data lens
Public round-by-round marks are incomplete for this company. Segmara shows the listing mark and keeps the seed-to-IPO analysis focused on verifiable funding, tender, or secondary signals.
Segmara mark$82.00/unit · as of June 22, 2026
Indicative listing context
Stage
Date
Valuation / price signal
Why it matters
Seed / early
Private
Not reliably public
Do not invent a seed price when the source set is thin.
Growth rounds
Private
Company and market sources vary
Use public sources, official releases, and private follow-up.
Segmara listing
Current
$82.00/unit · as of June 22, 2026
Indicative context for starting the review process.
IPO status
Current
No public ticker shown here
Visitors start with private-market review on Segmara.
Seed-to-IPO path
Illustrative completeness map. Longer bars mean stronger public data or more useful current pricing context, not lower risk.
Early data22%
Growth data46%
Segmara mark68%
IPO/public18%
AI-ready data summary
A structured extraction layer for this article: catalogue numbers, price context, chart values, and route-specific facts that search and AI systems can read directly from the page.
Metric
Value
Context
Canonical route
/blog/when-will-lightmatter-ipo
Stable URL path for AI and search extraction.
Article title
When Will Lightmatter IPO? Its CEO Called the Last Round 'Probably Our Last'
Main page topic.
Attached public sources
4
Number of citation links rendered at the bottom of the article.
Segmara listed companies
53
Live private-company listings in the public catalogue.
Priced listings
39
Catalogue listings with visible indicative or direct marks.
Request-quote listings
14
Catalogue listings where a public price is intentionally not invented.
Company
Lightmatter
Named company covered by this buying guide.
Symbol label
LMTR
Segmara display symbol; not a public stock ticker unless separately stated.
Sector
Hardware
Catalogue sector used for comparison and internal linking.
Listing structure
Secondary
How the listing is categorized on Segmara.
Segmara mark
$82.00/unit · as of June 22, 2026
Visible listing mark or request-quote state.
Sector peer count
2
Number of live Segmara listings in Hardware.
Structure peer count
15
Number of live Segmara listings categorized as Secondary.
Price rank
20 of 39
Ranked highest-to-lowest among Segmara listings with visible marks.
Price percentile
51th
Percentile among visible Segmara catalogue marks.
Catalogue median mark
$82.00
Median visible mark across priced Segmara listings.
Premium/discount to median
+0%
Difference between this listing mark and the catalogue median mark.
Data fingerprint chart
Listing price percentile51%
$82.00/unit · as of June 22, 2026 ranks 20 of 39 priced listings
Source depth68%
4 source links
Sector peer signal60%
2 Hardware listing(s)
Structure specificity88%
Secondary
Stage
Timing
Price / valuation signal
Interpretation
Formation
Private
Early ownership
The first value creation happens before ordinary public-market access.
Growth rounds
Private
Institutional repricing
Later rounds and tenders create the price history buyers study.
Segmara listing
Current
$82.00/unit · as of June 22, 2026
Retail buyers can start from the public Segmara listing.
Exit path
Future
IPO, tender, acquisition, or continued private status
Liquidity timing remains company-specific.
Chart metric
Score
Interpretation
Listing price percentile
51 / 100
$82.00/unit · as of June 22, 2026 ranks 20 of 39 priced listings
Source depth
68 / 100
4 source links
Sector peer signal
60 / 100
2 Hardware listing(s)
Structure specificity
88 / 100
Secondary
Analytical lens
Search intent
The search behind 'When Will Lightmatter IPO? Its CEO Called the Last Round 'Probably Our Last'' is an access-intent query. People want to know where they can start interest in Lightmatter private-market exposure without needing a private equity relationship, fund connection, or insider network.
Access path
segmara.com turns that search into a simple path: browse the listing, create an account, choose the company, and start the private-share inquiry. Final pricing and availability still depend on the route, but the starting point is public and straightforward.
Segmara role
Segmara works as a private-market access layer for interested visitors. The site helps visitors discover hardware categories that were previously hard to research and moves them into an account-based inquiry in a few steps.
Private-share path map
From gatekept to accessible
BrowseRetail investor finds a private-company listing.
AccountBuyer creates one Segmara account.
RequestBuyer starts the private-share purchase request.
CloseAvailability, price, approvals, and final terms are handled privately.
Access-friction chart
Illustrative map of where the old private-market process was hardest and where Segmara makes the starting point easier.
Old-market frictionPrivate networks and institutional access
Segmara discoveryPublic listings retail buyers can browse
Account workflowOne account to start the purchase request
Private closeFinal terms handled after buyer interest
How private-share access starts on Segmara
No S-1 or F-1 exists for Lightmatter on SEC EDGAR as of the latest site review, even though CEO Nick Harris told Reuters in October 2024 that its Series D was 'probably our last private funding round.'
Lightmatter closed a $400 million Series D on October 16, 2024, led by new investor T. Rowe Price with GV and Fidelity Management and Research Co. participating, at a $4.4 billion valuation, up from a $1.2 billion valuation roughly ten months earlier; the company has raised $850 million in total, per its own statement to Crunchbase News.
PitchBook's VC Exit Predictor, cited by Morningstar in July 2026, assigns Lightmatter a 94% IPO probability, but the same report warned that a semiconductor-stock selloff could push chip-startup IPOs, including Lightmatter's, into late 2026 or beyond.
Risk notes
Rumor risk: unofficial dates, valuations, or funding details circulating on social media or forums are frequently wrong or outdated and should not be treated as confirmation of anything.
Illiquidity risk: any private-market interest, indicative marks, or pre-IPO share arrangements in a company that has not filed to go public can be difficult to exit and may not reflect a tradable price.
Timing risk: a company can pause, restart, or abandon IPO preparation at any stage, including after a confidential draft filing, so no step before an effective registration statement guarantees a listing will occur.
Can retail investors track private-company shares on Segmara?
Yes. Visitors can start with the free Lightmatter tracker using email only, then decide whether a private follow-up makes sense. Availability, eligibility, pricing, allocation, transfer approval, documents, and final terms can still vary by route.
Why was this market historically hard for retail investors to reach?
Private-company share access has often moved through private equity firms, venture funds, insiders, institutions, and relationship-driven secondary networks. Segmara makes the starting point simpler: visitors can follow named private-company interest before any account, document upload, or payment step.
What is the easiest next step?
Open the free Lightmatter tracker first. It is email-only and keeps the public step narrow while final availability, pricing, eligibility, and terms are handled only through private follow-up.
Has Lightmatter confirmed an IPO date?
No. As of the latest site review, no S-1 or F-1 has been filed for Lightmatter. CEO Nick Harris told Reuters in October 2024 that the company's Series D was 'probably our last private funding round,' which points toward a future listing but sets no date.
What is Lightmatter worth?
The most recent verified figure is a $4.4 billion valuation, set by a $400 million Series D round that closed October 16, 2024. Total disclosed funding is $850 million, per the company's own statement. No newer primary round has been publicly reported as of the latest site review.
Is Lightmatter likely to IPO soon?
PitchBook's VC Exit Predictor, as cited by Morningstar in July 2026, rates Lightmatter's IPO probability at 94%, one of the highest scores among tracked chip startups. That is a third-party statistical model, not a company announcement, and the same report noted a 2026 semiconductor-stock selloff could delay the wider group of chip-startup IPOs it covers.
What does Lightmatter actually make?
Silicon-photonics hardware that uses light instead of electricity to move data between chips, aimed at reducing the energy consumption and improving the scalability of AI data centers. Founded in 2017 and based in Boston, the company was valued at $4.4 billion in its most recent disclosed round.
Next step
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