Bitcoin
Bitcoin reached the amount of 17 million coins on Thursday, the 26th of April. An important event in the world of cryptocurrencies happened thanks to the BTC.com mining pool on block 519,996. Due to the limitation of Bitcoin's issue to 21 million coins, at present 81% of the total amount of BTC have been issued. The first BTC in the amount of 50 coins was created on the 3rd of January, 2009, while the identity of the creator of the cryptocurrency, Satoshi Nakamoto, was still unknown. The generated first block is called the "genesis-block". According to Satoshi Nakamoto's algorithm, the reward is reduced by 50% every 210 thousand units. The second wave of reductions was in July of 2016 and since then it is 12.5 BTC. The CEO of Bitstamp Neich Kodrich recalled how Bitcoin emissions are controlled: https://twitter.com/nejc_kodric/status/989469203408343040 In case the Bitcoin protocol is not changed (on average, 10 minutes are spent on creating a new block), the next new BTC will be created in May 2140, which will have to wait 120 years.
"While 17 million BTC may sound like a lot, it's incredibly scarce - there won't even be enough for every current millionaire to own a whole bitcoin. Thankfully, each bitcoin is divisible into 100 million satoshis, thus there will always be plenty to go around!" -  CoinDesk quotes the engineer of startup Casa and one of the leading developers of Bitcoin Core, Jameson Lopp.
In addition, the publication noted some interesting information: it is technically impossible to reach 21 million  BTC, because not 50 BTC, but 49,99999999 BTC were mined on the 17th of May, 2011. The real identity of the miner is not disclosed, only his nickname is known, it is "midnightmagic". The causes of the accident have not been disclosed yet, but nevertheless it indicates that reaching the 21 million BTC mark will be impossible, since there will always not be enough 1 Satoshi. Thus, in case the amount of 21 million BTC is reached, Bitcoin will still keep operating. Perhaps this will be a good motivation for the miners servicing the network, since the commission on the transaction will be high. Subscribe to The Coin Shark news in Twitter: https://twitter.com/the_coinshark