Develops and manufactures Linear Generators to unlock the full potential of distributed power generation.
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Highest Bid
$ 260.80
Lowest Offer
$ 188.50
Last Trade
$ 234.00
Live Orders
1,298
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Overview
Mainspring Energy is a technology company focused on providing clean and reliable power solutions through its innovative Mainspring Linear Generator. Founded with the vision of supporting a net-zero carbon grid, Mainspring aims to deliver local power generation that can adapt to various fuel types and operational needs.
Mainspring Funding
Sign up to gain insights into Mainspring funding history, including the funding round, time period, and amount raised.
| Financing Round | Date | Amount | Price per share | Valuation |
|---|---|---|---|---|
| Round | Date | Amount | PPS | Valuation |
| Series F | Apr 14, 2025 | 258M | ||
| Series E | Sep 21, 2022 | 166M | ||
| Series E-1 | May 16, 2022 | 19M | ||
| Series E | May 16, 2022 | 106M | ||
| Series D | Mar 10, 2021 | 108M | ||
| Series C | Jan 25, 2018 | 58M | ||
| Series C | Aug 29, 2017 | 25M | ||
| Series B | Aug 12, 2016 | 40M | ||
| Series A-1 | Jun 14, 2011 | 7M | ||
| Series A | May 21, 2010 | 3M |
Access the PPS, Valuation details, and a wealth of other data by signing up. Source: Nasdaq Private Market
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Mainspring Management Team
Investors
40 North
Amazon's Climate Pledge Fund
American Electric Power (AEP)
Bill Gates
Canada Pension Plan Investment Board (CPPIB)
Centrica Innovations
Chevron Technology Ventures Investments
ClearSky Ventures
DCVC
Devonshire Investments
Fine Structure Venture
Gates Frontier
General Catalyst
Hanwha Venture Capital Corporation
KCK Group
Khosla Ventures
LGT Bank
Lightrock
Lineage Logistics
Louis Bacon
Marunouchi Innovation Partners
M&G Investments
Pictet
Princeville Global
Shell Ventures
Statoil Energy Ventures
Temasek
Mainspring Valuations & Financials
View real-time NPM data on Mainspring stock including daily Mainspring stock price estimates, valuation history, and historical share price information. Access Mainspring financing rounds, secondary trade levels, cap table data, and private company comparable transactions. Use NPM's private company valuation database to track Mainspring pricing across six independent market signals. Looking for private company due diligence data sources on Mainspring? Get in touch to learn more.
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FAQ
We have answers
Mainspring stock does not trade on public stock exchanges. Mainspring stock is considered a private security and you need to be an accredited investor to trade shares. To invest in Mainspring stock you can either buy shares directly through the company or work with a secondary trading marketplace like Nasdaq Private Market.
Learn more about the secondary market for private company shares on the investors page.
Mainspring Stock does not trade on public stock exchanges. In order to sell Mainspring shares you need to work directly with the company or with a secondary trading marketplace like Nasdaq Private Market. NPM has more than a decade of experience helping sell shares on the private market to our network of institutional investors.
Learn more about NPM services for selling privately held stock on the Employee Shareholders page.
Read more about how to sell private company stock on the private secondary market:
Nasdaq Private Market estimates that Mainspring price per share was $3.78 as of October 02, 2026. This Mainspring share value estimate (known as the NPM price) is based on market activity, publicly-sourced valuation data, and other proprietary information. With NPM Data and Intelligence premium for investors, you can get visibility into the Mainspring share price today and the factors driving Mainspring valuation estimates. Learn more about premium data here.
Read more about private company stock prices: Understanding the Bid-Ask Spread: How Buyers and Sellers Match on Price
There is no ticker symbol for Mainspring stock because it is a private company. Private companies do not have ticker symbols like public companies, they are identified primarily by using the company ‘street’ name or legal name.
Nasdaq Private Market currently works with employees, ex-employees, and other company investors. In order to sell Mainspring stock you need to receive the company’s approval, which Nasdaq Private Market manages on your behalf.
Learn more about selling privately held stock on the Employee Shareholders page.
Read more about how to sell shares of a private company and eligibility for selling privately held stock:
Currently, Nasdaq Private Market only works with accredited entities and institutional investors to purchase private company stock. In order to invest in Mainspring stock, you need to be an accredited entity or institutional investor.
Learn more about the Nasdaq Private Market tool kit for investors on the Investor Trading page.
Once you buy or sell, stock share ownership must transfer before funds are wired. With Nasdaq Private Market, clients leverage our patent-pending Transfer and Settlement technology which streamlines and manages transfer activity from match to settlement.
To learn more about private company stock Transfer and Settlement, check out the Transfer and Settlement page.
Mainspring is a private company and has not had an IPO. There is currently no Mainspring IPO price. Get started to begin exploring the Nasdaq Private Market Data and Intelligence database and gain access to actionable data related to Mainspring IPO.
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