Coinbase, the digital currency startup whose mission is to create an open financial system for the world, has raised $100 million in Series D funding.

It now has a valuation of $1.6 billion, making it the first startup in the world of crypto assets to become a unicorn, or company with a valuation greater than $1 billion.

The round was led by top tier growth-stage venture capital firm IVP, which has invested in more than 300 companies, including 106 that have have gone public. IVP has also invested in companies such as Dropbox, Netflix, Twitter, Slack, and Snap. The round also included Spark Capital, Greylock Partners, Battery Ventures, Section 32 and Draper Associates.

Coinbase had previously raised $117 million from Andreessen Horowitz, the New York Stock Exchange, Draper Fisher Jurvetson, USAA, BBVA and others.

As the main on-ramp in the United States from the traditional banking system to the world of crypto assets, Coinbase has benefited from the huge surge of interest in bitcoin, ether and new tokens due to initial coin offerings this year, as the market cap of all coins has risen from $18 billion on January 1, 2017, to $120 billion as of press time. It said in a blog post that it has experienced "unprecedented growth over the last year" and that it has exchanged more than $25 billion in U.S. dollars to digital currency. The Wall Street Journal previously reported that the company is "hugely profitable."

Concomitant with the surge in growth has been user complaints about lack of response to customer service tickets and delays in new user signups. To that end, the company announced that it plans, with its new funding, to expand its engineering and customer support teams.

Coinbase has also become one of the top institutional and professional crypto trading platforms in the U.S. with Global Digital Asset Exchange (GDAX). According to crypto asset data site Cryptocompare, among U.S.-based exchanges, it has the highest trading volume for the BTC-USD trading pair. The five-year-old startup plans to further build out its offering for professional traders and institutions and is opening a GDAX office in New York City.

The company also intends to use its new funding to develop its latest offering, Toshi, a Ethereum-based browser that makes possible apps that, for example, pay users for consuming an ad.

The company, cofounded by chief executive Brian Armstrong and Fred Ehrsam who left the company this past winter, has built up a reputation as one of the few safe, compliant exchanges in an emerging industry that is still very much in a Wild West phase and in which exchanges are still prone to hacks. (Read more about Coinbase's history in this magazine feature on the company.)

However, its cautious approach has sparked criticism from a community used to the fast-moving crypto industry. For instance, last week, a group within Bitcoin created a new version of the cryptocurrency called Bitcoin Cash, effectively giving every bitcoin holder an equal amount of Bitcoin Cash. When Coinbase announced it would not support Bitcoin Cash or even give Coinbase users holding bitcoins with Coinbase access to their Bitcoin Cash, users withdrew what equaled almost 50% of the bitcoins kept in cold storage on Coinbase. (However, the company did make 1.5% on the transfers back to bank accounts.) After an outcry from users who still held bitcoins on Coinbase, the company announced it would make Bitcoin Cash available to its users, but that it would not be available until January 2018.

Its reputation as a leader in cryptocurrency has also made it a target as the government figures out how to regulate this new technology that also acts as a form of money. Last fall, the Internal Revenue Service issued a John Doe summons on Coinbase requesting all the information on all its customers over a three-year period to catch people not reporting gains on their crypto assets when doing their taxes.

However, its position as a trusted gateway to the world of cryptocurrency has also enabled it to forge partnerships with mainstream financial institutions, such as a pilot that began this week on Fidelity, in which its customers will be able to view their Coinbase cryptocurrency balances from their Fidelity accounts.

Update, Thursday, August 10, 2017, 12:57pm: The article originally reported Coinbase makes 1.5% on all transfers of Bitcoin out of Coinbase, but the fee only applies to transfers back to bank accounts, not when coins are moved directly to a user-controlled wallet.