Bitcoin is called digital gold, because the properties of ordinary gold were incorporated into this electronic currency, initially when it was created. Based on the properties of gold, and attitudes towards him on the part of people, Bitcoin did.
Like gold, Bitcoin has a finite number, a limited number of 21,000,000 coins. The amount of gold is also limited on the planet, and looking far into space is too expensive to extract this resource there.
Like gold, Bitcoin with the expansion of the boundaries of use, and increasing interest from the people - is growing in price.
Like gold, Bitcoin can be mined by investing in the search for certain resources.
Like gold, with the development of the network of users, Bitcoin is not destroyed, but plus the presence of anonymity, with full transparency of operations throughout history.
As with gold, with an increase in price, Bitcoin becomes not a convenient means of payment for small amounts due to high cost and poor divisibility (high cost of transactions, although the opposite was intended).
Everything valuable is called 'gold.' For example, oil is black gold, and now Bitcoin is also called digital gold. Bitcoin is called digital gold because of its range of properties, which it is similar to gold and is valuable.
Bitcoin can be mined and its reserves are finite.
First of all, this name was received by Bitcoin due to limited volume. As of today, 80% of these coins have been mined, 20% is left. An interesting fact is that the mined gold is the same, and 20% is left in the bowels of the earth.

1. The complexity of mining.
2. Mining is harder and harder.
3. Impossible to fake.
4. As Bitcoin and gold can not be faked.
5. Cost.
6. Bitcoin has long maintained its high value, therefore, like gold, it attracts investors.
7. Divisibility.
8. Easy exchange.
   It is these similar indicators with gold, dubbed Bitcoin - digital gold. But gold is gold. This is a proven investment tool that has maintained its position for more than a decade. And bitcoin is a volatile, highly risky tool, which is also called a soap bubble, which can burst at any moment.