(Reuters) -Apollo Global Management, Oppenheimer, Jane Street and HSG, formerly known as Sequoia Capital China, invested in crypto exchange Kraken's recent funding round that valued the company at $15 billion, said two sources familiar with the matter.

Fortune reported last month that Kraken closed the $500 million round, but Reuters is naming the firms, which are major investors and financial players, for the first time.

Their participation underscores how institutional players are moving into the digital asset sector, which has benefited from U.S. President Donald Trump's pro-crypto stance and his administration's push for friendly regulations.

Qube Research & Technologies; Kraken's co-CEO Arjun Sethi; and Tribe Capital, a venture capital firm that Sethi co-founded, also bought into the fundraising round, which paves the way for the crypto firm to go public in coming months, one source said.

Spokespeople for Kraken, Qube and Jane Street declined to comment. Spokespeople for Apollo, Oppenheimer, HSG and Tribe Capital did not provide comment.

Kraken, one of the world's largest crypto trading platforms, is expected to confidentially file a registration statement for an initial public offering with the U.S. Securities and Exchange Commission by year-end, with plans to go public in the first quarter, one of the sources added, although it was unclear how the U.S. government shutdown might affect that timeline.

Several other crypto companies including Circle, Gemini and Bullish have capitalized on crypto exuberance with IPOs this year.

Kraken has been expanding aggressively, buying retail futures trading platform NinjaTrader for $1.5 billion in May and futures exchange Small Exchange from IG Group for $100 million this month, paving the way for the company to launch a fully U.S.-based derivatives platform.

Growing institutional and corporate participation in crypto markets has helped push up the value of major tokens over the last year. Bitcoin, the world's largest cryptocurrency, is up more than 20% so far this year, after hitting a record high above $126,000 this month.