Quartz is the latest media company attempting to cash in on the growing enthusiasm for cryptocurrency.

The online business-news startup is launching Quartz Private Key, a newsletter that aims to guide its subscribers through the often turbulent markets for virtual currencies such as bitcoin and Ethereum.

For $15 a month or $150 a year, readers will have access to a twice-weekly newsletter that summarizes and analyzes the rapidly shifting world of cryptocurrencies and the decentralized accounting technology that supports them. The newsletter is the first paid product that Quartz has released since it was acquired in July by the Japanese financial intelligence and media firm business intelligence firm Uzabase. 3966 2.62%

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A paid cryptocurrency newsletter hits multiple sweet spots for Quartz, which was an early adopter of both free newsletters and coverage of bitcoin, said Kevin Delaney, the co-president and editor in chief of Quartz. The company gauged reader interest in the product before it launched and managed to sign up about 50 paying customers weeks in advance, Mr. Delaney said.

In an interview, Mr. Delaney said the heightened interest in virtual currency opened up a niche for Quartz because many potential consumers don’t have the information they need to make informed decisions.

“Despite surging interest in them, cryptocurrencies remain opaque to most potential investors. It’s surprisingly difficult to find clear and useful information on the web,” Mr. Delaney said. “Quartz Private Key is stepping into that void with analysis of new coins, regulations, emerging uses of blockchain, and other information that’s essential to being a smart cryptocurrency investor.”

Quartz Private Key will face competition from other newsletters that focus on cryptocurrency. Anthony Pompliano, a founding partner at the asset management firm Morgan Creek Digital, writes a newsletter called “Off the Chain” that provides daily analysis of cryptocurrency markets.

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Mr. Pompliano says the newsletter, which costs $30 a month, has already attracted “thousands” of subscribers. CoinDesk, a news site that specializes in digital currencies, also offers a mix of daily and weekly newsletters. And many major news organizations, from Bloomberg to The Wall Street Journal, write regularly about the world of cryptocurrencies.

Uzabase bought Quartz for between $75 million and $110 million, according to The Wall Street Journal. Uzabase said the acquisition was driven, in part, by the potential of working with Quartz to build a paid subscription business.

The deal was structured with a so-called earn-out, with the final acquisition price determined by Quartz hitting revenue goals. A company spokesperson said Quartz was still on track to meet its projected revenue goal of $35 million to $38 million for 2018. Last year, Quartz booked $28 million in revenue but wasn’t profitable.

Like many media companies, Quartz is turning to subscriptions as the market for digital advertising becomes increasingly competitive. As major tech firms, including Alphabet Inc.’s Google and Facebook Inc., tighten their grip on new digital spending, media outlets are looking for alternate revenue sources.

Quartz’ U.S. readership has held steady over the past two years, according to data from web analytics firm comScore. In 2017, Quartz attracted about 11.87 million average monthly U.S. visitors; so far this year, Quartz has averaged about 11.67 million monthly U.S. visitors, according to comScore.

For Quartz, paid products have been a long time coming. In 2017, the company acquired Intelligentsia.ai, an artificial intelligence research firm, and explored the creation of a paid research business before shelving the idea. Quartz also ran a high-end paid events business before canceling its flagship conference last year.