Mobile social app company Snapchat has secured $175 million in a fresh funding round.

A source familiar with the matter told Reuters of the cash injection, which has been backed by Fidelity Investments and other investors.

According to the source, the "flat funding round" is an extension of last year’s Series F.

According to financial intelligence company PrivCo, a flat round is a round of financing where investors purchase stock from a private company at the same valuation as the price placed upon the company by earlier investors.

In May 2015, the company closed a funding round of $537 million. In December 2014, Snapchat closed another round of $485 million.

Snapchat has now raised over $1.4 billion, and the company is valuated at $16 billion, according to the WSJ. Snapchat is the world’s sixth largest venture-backed company.

The paper also reports that Fidelity bought Snapchat shares at $30.72 per share in February this year, the same value it spent in March 2015.

Snapchat was created in September 2011. The mobile app allows users to send pictures and videos, which can be edited or not, to their contacts. Once one gets the message, he/she will have between one to ten seconds to see the media file.

The company has also introduced a messaging feature to the service. Over 100 million people use the network with eight billion videos being watched a day.

Snapchat recently fell victim of a phishing attack, which leaked employees’ payroll data after a CEO email scam.

The company issued a public apology to employees via its blog, admitting "real remorse and embarrassment".