A photo illustration of the digital Cryptocurrency, Bitcoin, is seen on September 13 2018 in Hong Kong, Hong Kong.

Binance, the world's largest cryptocurrency exchange by trading volume, is still profitable despite last year's market meltdown, its chief financial officer said.

Last year saw the prices of major virtual currencies plunge dramatically. Bitcoin, the most valuable crypto, is down 80 percent from a near-$20,000 record high it set in December 2017.

"To date, even in this bear market, we still run a profitable business," Binance CFO Wei Zhou told CNBC in a phone interview Wednesday.

The company doesn't disclose its financials publicly, he said, and media outlets have been publishing estimates based on publicly available metrics.

One report, by industry publication The Block, estimates Binance made $446 million last year, based on an analysis of how much it spent to buy back units of its token, called BNB, using its net profits.

The start-up's Chief Executive Changpeng Zhao told Bloomberg in July that Binance was targeting a net profit of between $500 million and $1 billion in 2018.

The company has only been around since July 2017, but has become a dominant force in the nascent sector. It raised $15 million in its initial coin offering — a funding alternative to venture capital where start-ups sell new crypto tokens instead of equity.