You have to admire Pavel Durov’s audacity.

Over the past few months, the CEO of Telegram convinced 81 accredited investors, including Silicon Valley giants Sequoia Capital and Benchmark, to give him $850 million in a presale of his company’s cryptocurrency in advance of an initial coin offering, or ICO. Now he’s trying to raise even more money from accredited investors before the coin gets offered to the public in a secretive second presale.

This week, investors got an email explaining that Telegram is doing another private presale, four sources with knowledge of the deal told The Verge.

The exact amount to be raised is still being determined, according to one source, but two other sources said Telegram is estimating it will be around the same size as the first round, which would bring the total raised to over $1.6 billion before the ICO even opens up to the general public. Telegram’s offering was already the largest ICO ever, dwarfing the previous record of $232 million. Telegram declined to comment on the second presale. Sequoia Capital declined to comment and Benchmark did not respond to questions.