The Chinese crypto industry giant BitMain, which specializes in producing equipment for bitcoin mining and has one of the largest bitcoin pools, is to this day the largest manufacturer of ASIC miners and the largest player in cryptocurrency mining, despite the fact that its share declined by the end of 2018 — the share of pools affiliated with BitMain fell from 53% to 39% of Bitcoin's hashrate.

BitMain began 2018 in a position that technically allowed it to single-handedly carry out a "51% attack" on the Bitcoin blockchain — its own mining pools and the ViaBTC affiliated with it controlled more than half of the hashrate. It would seem that, following a year that significantly thinned the ranks of small players, who often operate with not the most modern equipment, the position of the largest manufacturer of that very equipment should have strengthened even more, but this did not happen. As the analytical publication Diar notes, BitMain entered 2019 controlling less than 40% of the hashrate. At the same time, the role of miners not belonging to any of the largest pools, grouped into the "unknown miners" category, on the contrary, grew — their contribution to the common cause was estimated at 6% in January 2018, and at 22% in December. Here, however, there is one important detail — technically there are no factors that would oblige a miner to disclose their affiliation with one pool or another.

That is, the same BitMain, if for some reason it was necessary for it to do so, could simply "hide" part of the capacity under its control in the shadows, the publication notes. Still, even 39% of the hashrate is anyway more than any other market participant has. This, in turn, makes it possible to assume with a high degree of probability that the larger part of the mining reward, which reached $5.8 billion for the year, also went to BitMain. Especially considering that in January, while the Chinese miner manufacturer's position was particularly strong, the reward amount was $1.2 billion, and in December — almost six times less.