Working at startups is always a gamble.
But if you get your foot in the door early enough at the right company, you could end up a millionaire.
Inspired by a 2012 Quora thread, we decided to come up with our own list of companies you should join if you want to make some serious cash in four years, assuming you're able to negotiate a bunch of stock options when you join.
We've included employee count for each company. For startups whose employee headcounts we didn't have access to from our own reporting, we consulted Pitchbook, a private equity and venture capital database that tracks information about companies.
The companies on this list are blowing up — some are early-stage, some are more mature, but they're all highly valued and fast-growing. You'll want to get hired before they take off further.
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Thumbtack

Headquarters: San Francisco
Investment raised to date: $273.2 million
Employee count: 745
Founded: 2008
Thumbtack, one of the newest entrants to tech's still-booming "unicorn club," is a platform that matches professionals like personal trainers or electricians with potential customers.
Earlier this year, Thumbtack raised $125 million at a $1.3 billion valuation. That's quite a spike from the company's $750 million valuation last year. Thumbtack handles job listings and marketing for people providing local services, and collects interested customers.
Lyft

Headquarters: San Francisco
Investment raised to date: $1.01 billion
Employee count: 2,169
Founded: 2012
Though it's often compared as a smaller rival to Uber, Lyft is a huge entity in the on-demand ride-hailing market. With a $2 billion valuation, Lyft operates in about 65 US cities, and recently announced a huge partnership with Didi Kuaidi, the highly valued Uber rival, to expand its footprint overseas.
Lyft's investors include Rakuten, Alibaba, and even Carl Icahn. This year alone, Lyft raised two major rounds of funding— $530 million in March and another $150 million from Carl Icahn in May — rebranded with a more sophisticated look, and announced huge growth for the company.
Zenefits

Headquarters: San Francisco
Investment raised to date: $583.6 million
Employee count: 1,445
Founded: 2013
Zenefits, a startup aimed at making administrative tasks such as payroll and benefits easier, is shaping up to be one of the fastest-growing cloud companies ever, in terms of both revenue of number of users.
In May, Zenefits raised $500 million in Series C funding, bringing the company’s valuation up to $4.5 billion. Only two years old, Zenefits employs 1,000 people and has 10,000 customers.
See the rest of the story at Business Insider
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