Carta Inc., a startup that makes software to manage equity stakes in other startups, is wrapping up a round of investment that would value the seven-year-old company at about $1.8 billion, according to a person familiar with the matter.

The company helps venture capitalists, as well as startup employees and other stakeholders, track and manage the shares that they own. It also helps companies manage other aspects of their stock, such as fair-market valuations and secondary sales.

Carta’s product becomes more useful as more startups stay private longer and have more complicated capitalization tables, though some of its customers have also gone public while continuing to use the service. The company has plans to expand to help venture capital firms’ limited partners, such as endowments and pensions, manage their portfolios.

Venture firm Andreessen Horowitz is leading the $300 million round, said the person, who asked not to be identified because the details are private. It’s a quick step up from Carta’s last bout of venture funding just three months ago, when it raised $80 million at a $800 million valuation.

A spokeswoman for Carta declined to comment. The funding was previously reported by the tech news site The Information.