The social messenger Telegram has closed the second round of its token sale, attracting $850 million. Overall Telegram attracted $1.7 billion making it the largest ICO in history.

Brothers Pavel and Nikolay Durov filed a notice with the US Securities and Exchange Commission (SEC), claiming that they raised $850 million from the Grom token sale. The investment proceeds will be spent to develop their blockchain project Telegram Open Network (TON).

According to the documents published on the SEC's website, the ICO was conducted by two companies, TON Issuer Inc. and Telegram Group Inc., run by the Durov brothers. The second round began on 14 March. 94 investors participated in the ICO, but their names are not disclosed.

Officially the token sale is called "Agreement on the purchase of cryptocurrency."

During the first round of the ICO, which was held in late January-early February, the Durov brothers also raised $850 million

The first round of the ICO took place from 29 January to mid-February. On 13 February, the Durovs reported their results, filing a notice with the SEC. Within the first round, they managed to attract $850 million from 81 investors.

In December 2018, the third round of funding may be held. It may be open to the public or closed, as the previous two, wrote Vladimir Smerkis, co-founder of the crypto investment fund The Token Fund. The distribution of tokens is also tentatively scheduled for December 2018.