At this point, I don’t know the geographical distribution of it, but here is a good table that shows Bitcoin distribution by addresses:
As you can see, only two addresses store over 100,000 BTC each. Together, these addresses keep 1.65% of all the Bitcoins available today, which is the equivalent of $2.1 billion.
On the bottom side, around 13 million addresses, or 57% of them (the majority), store up to 0.001 BTC. However, all this majority of available addresses keep only 0.01% of the total Bitcoins, which is a bit weird, right?
Then, over 4.2 million addresses (which is about 18.7% of the total number of addresses today) hold 17 thousand BTC in total. Each of these has a balance up to 0.1 BTC.
If we check the chart, we can see that 90% of all the addresses hold less than 0.7% of Bitcoin. The combined value of this overwhelming majority of addresses is around $950 million – so it doesn’t even reach $1 billion.
This shows that there is a great disproportion in Bitcoin distribution, and this is also true about Bitcoin mining – there is a visible monopoly.
Anyway, it seems that those 2 wallets at the top are owned by crypto exchanges.
Bitcoin distribution is more disproportionate that wealth distribution:
Who Owns All the Bitcoins – An Infographic of Wealth Distribution – CryptoCoinsNews
When it comes to Bitcoin distribution by country, it’s more difficult to assess it. Generally, we can speak in therms of Bitcoin trading volume, but it is a variable indicator. For example, China was the biggest players, but after it banned ICOs and local exchanges, the market moved to Japan, South Korea, and other countries.