On Our Radar: Deals we are paying attention to for their impact on industry.

Money transfer startup TransferWise, which counts Virgin Group founder Richard Branson and PayPal founders Peter Thiel and Max Levchin among its investors, is preparing to sell a stake in itself for $300 million to fund further expansion. The round would value the U.K.-based company at $4 billion, according to a report from Reuters news agency that cites sources familiar with the plans.

Goldman Sachs & Co. will underwrite the round, the sources said, according to Reuters.

Using new technology and smartphones, TransferWise is one of a crop of fintech startups disrupting the large-margin money transfer business once controlled by large banks and firms such as Western Union. An increasing number of foreign workers in countries around the world sending remittances home to their families in their countries of origin offer a ready market for low-cost transfer programs.

TransferWise was founded in 2010 by two Estonians working in London who needed to convert pounds to euros. Today, more than 4 million customers move more than $4 billion dollars a month through TransferWise, saving about $4 million in bank fees daily, according to the company.

TransferWise has 11 offices, with over 1,300 employees, across four continents. Its borderless account lets customers hold over 40 currencies at once and convert them at any time. As many of its customers don’t qualify for credit cards in the countries in which they work, TransferWise also issues a debit Mastercard.

TransferWise last round of fundraising came in 2017, when it had a valuation of $1.6 billion. Investors included Old Mutual Global Investors and venture capital firm IVP, according to Reuters. Last year, TransferWise had an operating profit of 9.5 million pounds on revenue of 117 million pounds.

The company says it plans to open an office in Brussels soon, to avoid any complications if the United Kingdom carries out plans to leave the European Union.

Last week, Rewire, an Amsterdam-based startup that’s developed an international banking platform for expatriate workers, raised $12 million in Series A financing, led by venture fund Viola Fintech, which is owned by Israeli tech firm Viola.

In March, MasterCard agreed to acquire Transfast, a global cross-border account-to-account money transfer network. Transfast is active in 125 countries and has relationships with more than 300 banks and financial institutions, the company said. It’s backed by private equity funds GCP Capital Partners and Apis Partners. There’s been no word on whether the private equity investors will fully exit their positions in Transfast after its acquisition by MasterCard.

According to a recent report by Research and Markets, India is the largest remittance-receiving country in the world, followed by China. The U.S. remains the largest source of remittance money.

Declining costs of remittances and a rising number of migrants are key drivers for market growth, according to the report. Key players include PayPal Holdings Inc., Western Union, Euronet, and MoneyGram international. The big players are under pressure from international organizations to reduce remittance fees, opening the door for new players with lower cost structures, such as TransferWise.