$1.6 billion bitcoin exchange Coinbase continues its acquisition spree, snapping up another small crypto company

Anthony Harvey / Stringer

Coinbase CEO Brian Armstrong

• Coinbase's M&A spree continues with the acquisition of Earn.com, which the company announced Monday.
• This is the company's second acquisition announcement in a week.

Coinbase's acquisition spree continues.

The $1.6 billion cryptocurrency exchange announced Monday that it has acquired Earn.com, a crypto company founded by Balaji Srinivasan, a former general partner at Andreessen Horowitz. Srinivasan is joining Coinbase as its first chief technology officer, a blog post by the company said.

The news comes just a few days after Coinbase announced it acquired Cipher Browser, a cryptocurrency wallet company that lets users store ethereum-based tokens.

It was reported by CoinDesk's Pete Rizzo in March that Earn.com was in talks with Coinbase. The company, which rebranded at the end of 2017 from 21.co, provides a platform that allows users to earn cryptocurrency by answering emails.

"We're going to be doubling down on the Earn business within Coinbase, as they have built a paid email product that is arguably one of the earliest practical blockchain applications to achieve meaningful traction," the company said.

My colleague Becky Peterson has reported on Coinbase's M&A ambitions. Coinbase hired its first M&A boss in March to lead a new push for acquisitions and partnerships to expand its opportunities in the booming market.

Still, some market observers think Coinbase is biting off more than it can chew. CoinRoutes founder Dave Wiesberger told Business Insider the company should focus its resources on understanding markets, regulations, and developing their trading technology, which is not at the same level as more established exchanges such as the NYSE or Nasdaq.

"They have failed to consider the implications of these topics along with understanding institutional needs, including how and why dark pools evolved, and the nature of of fragmentation in displayed markets," Weisberger said.

To be sure, Coinbase's institutional grade exchange, GDAX, is working on more mature offerings such as advanced order types and products tied to market data.

Also, it is looking to hire a head of market structure to "develop marketplace improvements such as new order types, liquidity incentive programs, and market safeguards," a recently posted job ad said.