Photonic computing / AI interconnects · Updated 6 August 2026
Lightmatter's secondary market price is $84.85 per share, implying a valuation of $4.65B, as of 5 August 2026.
Lightmatter builds photonic (light-based) computing hardware for AI infrastructure: the Envise photonic processor for AI acceleration, and the Passage photonic interconnect for high-speed chip-to-chip networking inside AI supercomputers, aiming to cut the power consumption of AI compute and data movement.
Founders: Nicholas Harris, Darius Bunandar, Thomas Graham
Lightmatter last marked at $84.85 per share on 5 August 2026, an implied valuation of $4.65B. Secondary Flow refreshes this mark every day from publicly observable private-market activity. Private-company prices are indications rather than executed trades: they carry wider spreads than listed equities, they can move without any news, and a transfer still needs the issuer's consent to settle.
At the current secondary mark of $84.85 per share, enter your holding to estimate its value. This is an indicative valuation of common stock before transfer restrictions, taxes, fees, and any liquidation preference held by preferred shareholders, so it is a reference point rather than a realisable price.
| Shares held | Estimated value |
|---|---|
| 100 | $8,485 |
| 500 | $42,425 |
| 1,000 | $84,850 |
| 5,000 | $424,250 |
| 10,000 | $848,500 |
| 25,000 | $2,121,250 |
Secondary Flow does not make buy or sell recommendations. What it does is lay out the evidence so you can reach your own view.
Lightmatter scores 35/100 on Secondary Flow's composite model, which weighs founder and investor quality, sector momentum, valuation against public comparables, and secondary-market pricing. Its implied valuation sits 0.0% below the level its public comparables would imply. The secondary mark is 5.7% above the last primary round, so a buyer today is paying a premium to the price the last institutional investors paid. Secondary-market demand reads 68/100 (warm).
See the methodology for how each factor is weighted and how the model is backtested against realised outcomes.
| Round | Date | Raised | Valuation | Step-up |
|---|---|---|---|---|
| Series C | May 2023 | $154M | $1.2B | - |
| Series D | October 2024 | $400M | $4.4B | +266.7% |
Celestial AI, Ayar Labs, NVIDIA
Lightmatter's most recent secondary-market price on Secondary Flow is $84.85 per share, as of 5 August 2026, implying a valuation of $4.65B. The mark is the median of 4 independent secondary-market venues. Secondary prices are indications compiled from publicly observable activity, not executed trades, and they move between updates.
At $84.85 per share, 100 Lightmatter shares are worth about $8,485, 1,000 shares about $84,850, and 10,000 shares about $848,500. Use the calculator on this page for your own share count. This is an indicative mark on common stock before any transfer restrictions, taxes, or fees, and the price a holder can actually realise may differ.
Lightmatter's secondary mark is 5.7% above its last primary round, which valued the company at $4.4B.
Secondary Flow does not give buy or sell recommendations. What it does give you is the evidence: Lightmatter scores 35/100 on the composite model, which weighs founder and investor quality, sector momentum, valuation versus public comparables, and secondary-market pricing. Its implied valuation sits 0.0% below the level its public comparables would imply. Read that alongside the price, the premium or discount to the last primary round, and the funding history on this page, and see the methodology for how each factor is weighted.
Lightmatter was last valued at $4.4B post-money in its Series D round (October 2024). Its current secondary-market mark implies $4.65B.
Secondary Flow is a research tool, not a broker-dealer or a marketplace, so it does not execute transactions in Lightmatter or any other private company. Private-company shares typically change hands through a company-approved tender offer, a direct transfer subject to the company's right of first refusal, or a regulated secondary marketplace, and most transfers require issuer consent. Secondary Flow tracks the resulting prices.
Not investment advice. Figures are compiled from publicly available sources believed reliable but not independently verified, and provided “as is” without warranty. Secondary-market prices are indications, not executed trades. Secondary Flow is an independent research tool, not a broker-dealer or investment adviser; company names and trademarks belong to their respective owners (no affiliation or endorsement implied).