$BTC
Total number of bitcoins available: only 21 million units
Number of bitcoins mined until May 2025: approximately 19.7 million
Number of lost bitcoins: estimated at 3 to 4 million (due to lost keys or forgotten wallets)
Start of mining: year 2009
Expected end of mining: around the year 2140
The number of new bitcoins decreases every 4 years through an event known as "halving"
The last halving occurred in April 2024, and the reward became 3.125 bitcoins per block
After mining ends, miners' rewards will come only from transaction fees
Mining difficulty is gradually increasing and requires advanced energy and equipment
Currently, less than 1.3 million bitcoins remain to be mined