Bitcoin is a decentralized cryptocurrency, but as it happens with fiat money, bitcoins are distributed unevenly.
In math language, they follow a variant of the Pareto distribution. A Pareto distribution is often used to describe the allocation of wealth among individuals. Its main idea is that a large portion of the wealth of any society is owned by a small percentage of people. This idea is expressed simply as the "80-20 rule" (or the Pareto principle) which says that 20% of the population controls 80% of the wealth.
That should be the situation in Bitcoin as well. But, in fact, as justcryptonews.com has reported, bitcoin distribution is even more uneven.
According to data published by bitinfocharts.com for 2017, a 58.1% of all bitcoin addresses hold a maximum of 0.001 BTC each. These are 12,213,838 addresses and the total sum of bitcoins they hold is just 2,186 BTC or a mere 0.01% of the total number of BTC in circulation today. The value of these coins is a little above the $12 million mark.
Another 18.1% (3,811,060 in absolute numbers) of all bitcoin addresses hold 0.001 to 0.01 BTC with a total of 14,928 BTC. This number is just 0.09% of all bitcoins minted with value at $83 million.
Thus, the vast majority 76% of all valid bitcoin addresses hold a tiny fraction of all bitcoins: just 0.1%!
There are also 2,982,301 (or 14.19%) bitcoin addresses which hold 0.01 to 0.1 BTC. The total bitcoins they hold is 93,201 BTC or just another 0.56% of total bitcoins.
Next, there are 1,359,848 (or 6.47%) addresses which hold 444,325BTC or 2.67% of all bitcoins. Each one of them has a balance 0.1 to 1 BTC.
This is another significant statistic: 96.89% of all addresses (58.1+18.13+14.19+6.47 = 96.89) hold a maximum of 1 bitcoin each. And their total balance in bitcoins is just 3.33% of all bitcoins minted today (2.67+0.56+0.09 + 0.01 = 3.33).
So, the rest 96.66% of all bitcoins today are owned by a tiny 3.11% of addresses.
Thus, in bitcoin, only 3% of the population (addresses) controls over 96% of the wealth (bitcoins).