There are only 4.2 Million Bitcoins Left to Mine.
As of 13th January 2018 16,800,000 Bitcoins have been mined which means that only 20% of Bitcoins have been left for mining as there is a total supply of 21 Million Bitcoins. The supply will never be increased as Satoshi Nakamoto set the number to 21 Million Bitcoins ever to be found. Since the protocol was introduced to the public in 2009 till now no one has been able to break rules of 21 Million supply cap.
However skeptics believe that the supply could be manipulated by weaknesses like Sybil Attack or 51% control.
Read more about weaknesses here https://en.bitcoin.it/wiki/Weaknesses
Personally, I think that all these weaknesses are possible to be exploited Theoretically Only. Practically in real world scenario these weaknesses cannot be exploited in such a way that will compromise or endanger the entire Bitcoin protocol. Let me know what you think about it.
The difficulty to mine bitcoin has also increased. You can check out the chart here https://blockchain.info/charts/difficulty
The increasing difficulty will make it necessary for the miners to be updated in order to continue making profits.
As 80% of Bitcoins have been mined the price may also skyrocket as the conventional economics states that the price of a commodity rises on account of higher demand.
It will be really interesting to see what happens next.
Feel free to ask me any doubts you have. Let me know what you think will happen next.
Image courtesy https://news.bitcoin.com