NextView Ventures, one of few seed-stage venture firms in Boston, is looking to raise at least $50 million for a third fund, shows an SEC filing that was processed yesterday. The firm closed its second fund with $40 million in 2014 and its debut fund with $21 million in 2012.

NextView was founded in 2010 by three former veterans of other venture firms: Dave Beisel, whod previously worked for Venrock; Rob Go, who was formerly with Spark Capital; andLee Hower, a former investor with Judith Capital.

Theyve seemingly worked hard to raise theprofile of the firm over that period, too. Go, for example, posts two or three pieces of analysis or advice each month to hiswidely read blog. (One of his most recent posts compares the process of sourcing venture deals to the process of drumming up customers for a software company, including nurturing leads over an extended period.)

The firm typically writes checks of between $100,000 and $1 million. Some of its newest investments include GetHuman, a four-year-old, Boston-based startup that fights peoples customer service battles for them (NextView led a $3 million seed round in the company last month), and Optimus Ride, an MIT spinoff at work on self-driving technologies. NextView led a $5.25 million seed round in the company in October.

At least 13 of NextViews portfolio companies have been acquired, shows Crunchbase data. Most recently,Farmeron, a farming data startup that had raised $4.3 million, was acquired by privately held Virtus Nutrition for undisclosed terms.Another company, seven-year-old, Boston-based Objective Logistics, a maker of employee performance software that had raised $7.6 million from investors, was acquired in June by the cybersecurity company Bit9in a reported acqui-hire.

NextView was also an investor in the mobile ad startup TapCommerce, acquired by Twitter in 2014 for a reported $100 million. The company had raised $11.7 million altogether.

Other seed-stage funds in Boston include the sector-agnostic firmRomulus Capital; Bolt (which focuses on hardware startups), Founder Collective (whose partners are also the firms biggest investors), Converge Venture Partners (mostly enterprise focused) and Boston Seed Capital(it funds internet, consumer and B2B startups).

Another Boston-based early-stage firm, the Experiment Fund, imploded earlier this year following infighting between the firms two general partners.

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