Ride-hailing app operator Uber became the largest venture-capital-backed company after it raised more than $1 billion from Microsoft, and Indian giants Tata Capital and Bennett Coleman & Co., in the latest series F round, valuing the company at more than $50 billion. The current round took place only seven months after Uber’s previous round, when it raised a massive amount of $2.8 billion at a $41 billion valuation, reflecting a 24% surge in Uber’s valuation in just seven months.

Note: You might be interested in our earlier coverage of a potential Uber IPO.

The San Francisco-based ride-on-demand startup is trying to expand globally even while it struggles with many difficulties on the way. These include problems in getting legal permits to operate in certain countries, competition from local ride-on-demand services, and pressure from local taxi organizations. At the same time, Uber faces a labor lawsuit over drivers’ rights in its home state of California. To fight back on all fronts and be able to grow Uber, massive amounts of money are needed, and this it partially receives from its frequent and huge funding rounds.

As shown in Chart 1 below, Uber raised more than $5.5B since 2010, when it raised more than $1B in three different rounds. Uber’s real boost in valuation happened after series C, when the company’s valuation surged 14.5X from $3.5B in series C to $51B in series F.

Uber succeeded in raising these impressive amounts of funding thanks to its leadership position in the U.S., as well as its broad global presence, revenue growth, and future growth potential. Comparing Uber’s global spread to its rivals’ reveals that Uber, without a doubt, has the widest global spread; it operates in 60 countries worldwide, and its biggest competitors, globally, are the Israeli Gett, which operates in U.S, Britain, Russia, and Israel, and the Singaporean GrabTaxi, which operates in six Southeast Asian countries.