Financial technology firm Revolut now has 2 million users signed up to its platform and is planning to launch a commission-free trading service.

The London-based start-up said Thursday that its trading platform, called “Wealth,” would let users invest in a range of firms listed publicly in the U.K. and the U.S., in addition to other instruments including exchange-traded funds (ETFs) and options.

ETFs are securities that let traders invest in a basket of assets such as shares or bonds. Options are contracts that give investors the right — but not the obligation — to buy or sell an asset at an agreed price and date, allowing for price speculation or risk reduction.

Revolut doubled its user count just months after it said it had passed the 1 million user mark in November 2017. Its planned commission-free trading service would compete with the likes of the U.K.’s Trading212 and U.S. firm Robinhood.

“For many years, people have felt frozen out of trading by high fees and clunky interfaces, so Revolut are aiming to make investments cheap, simple and completely mobile,” Nikolay Storonsky, Revolut’s co-founder and chief executive, told CNBC.

The company has widened its product offering into new areas such as cryptocurrency and savings as of late. It started out predominantly as a money management app offering currency exchange at the live currency conversion rate and has since signaled further expansion into banking by offering current accounts and last year applied for a European banking license.

“While the cryptocurrency feature has definitely played a part in our growth, our financial marketplace of products have also helped hugely in enticing people to join Revolut,” Storonsky said. Revolut’s marketplace gives users access to insurance and credit products from a variety of providers, similar to a feature offered by rival fintech firm Starling.

It is currently only available in Europe, and is most widely used in the U.K. The firm is looking to expand its presence to the U.S., Canada, Singapore, Hong Kong, Australia and New Zealand within months.

Revolut said it expects to launch the trading platform next year and is in the preliminary stages of building it. The service will be available to all of its customers, including those in the new markets it plans to expand to.

The firm counts itself among several of Europe’s so-called challenger banks — predominantly digital banks looking to compete with larger lenders. German challenger bank N26 recently announced it has 1 million users signed up to its platform. Revolut generates $2 billion a month in transaction volume, while N26 has a monthly transaction volume of $1.17 billion.

Storonsky said Revolut was not concerned by such fintech competitors because it expects its main competition to come from tech giants like Apple, Amazon, Facebook and Google.

“They have huge amounts of customer data, capital and employees that can help them to easily begin breaking into the banking space,” he said.

Revolut recently joined the ranks of Europe’s unicorns by surpassing $1 billion in market value after a $250 million investment led by venture capital firm DST Global.