Popular mobile app Snapchat has raised $175 million in a new round of funding, a Reuters source has confirmed. The latest round for the free video messaging service was a "flat" one, with the company's valuation stuck at last year's figure of $16 billion.

The main source of funding came from Fidelity Investments, one of the largest mutual fund and financial services companies in the world.

Shares were bought at $30.72 per share in February – the same price Fidelity snapped up shares in March 2015.

While Snapchat is the sixth most highly-valued venture-backed company around, the stagnation in its value suggests it previously expanded at too quick a rate and that investors' expectations are now readjusting accordingly.

Snapchat partnered up with Viacom in February, giving Viacom exclusive rights to sell advertising related to the mobile platform.

Not all of its media relationships are so harmonious. Instagram quietly took the decision to ban its users from linking to Snapchat (and Telegram) on their profiles this month.