GBMiners.

GBMiners was the first Bitcoin mining poolMining poolA group of miners who share the work of finding blocks and split the rewards, so each gets paid steadily instead of rarely. based in India. Its co-founders were Nikunj Jain and Amit Bhardwaj, who owned most of its early mining power, and Bhardwaj’s company Amaze Mining and Research said in 2017 that it ran the pool. Jain and Ayush Varshney, of Darwin Labs, a firm in Gurugram, ran it day to day. Its first block, 427,549, came on 30 August 2016, and within two months it had nearly 5% of Bitcoin’s mining power. In all it found 2,093 blocks.

GBMiners paid its miners once a day. In 2017 its website said it shared out what its blocks earned by each miner’s recent work, a method called “pay per last N shares”, or PPLNS; by 2018 it said it paid a set amount for each piece of work, by a method it called PPS+. So each GBMiners block’s first transaction paid the reward to the pool’s own addresses, and the pool paid its miners separately. These are payments to the pool’s miners, separate from the transactions confirmed inside the block.

Bhardwaj also ran GainBitcoin, which sold “cloud mining” contracts promising 10% a month in bitcoin for 18 months. India’s Central Bureau of Investigation (CBI) says its payouts depended on bringing in new investors, and that it later switched them to its own token, MCAP, worth much less than bitcoin. In 2017 a GainBitcoin marketer and the scheme’s investors told The Caravan magazine that it mined through GBMiners; Bhardwaj said there was “no relationship” between the two.

In April 2018 Pune police arrested Bhardwaj over GainBitcoin, and later that month Jain and his partner Sahil Baghla. Police told the court that, as part of the conspiracy, the two had built the websites of “GB Miner” and a bitcoin payment service. In June 2018 police named them in one of the case’s two charge sheets, and in July 2019 the Bombay High Court granted them bail; no trial verdict against either of them has been found. GBMiners found no blocks after 15 April 2018, and no announcement of its closure was found. Bhardwaj died in January 2022 while on bail. In December 2023 India’s Supreme Court handed all the GainBitcoin cases to the CBI, which was still investigating them in 2025.