Studies of the cryptocurrency market have revealed a high concentration of bitcoins in the hands of a narrow circle of investors and crypto exchanges. This is reported by analysts, warning that such a situation can lead to various kinds of manipulations in the market. It is worth noting that about 5 million bitcoins (which is almost a third of the total issued volume) were controlled by about 10 thousand investors as of the end of 2020. About a third, 5.5 million bitcoins, were controlled by intermediaries, in particular, crypto exchanges. About 8.5 million bitcoins were concentrated in the hands of individual investors. At the same time, the authors of the study do not exclude that some of the largest addresses may be controlled by the same person. According to them, the high concentration makes bitcoin subject to systemic risk and implies that most of the benefits from its further use and implementation are likely to disproportionately fall on a small group of participants. The concentration of miners turned out to be even higher: 10% of miners control 90% of bitcoin's mining capacity. Experts fear that high concentration can make the bitcoin network vulnerable to an attack, as a result of which a group of miners or even one of them can gain control over it.