As far as I know bitcoin have limited supply, and according to the articles that I have read it is about 21 million. I hope that this supply will never end, and I hope also that shortage will not occur. 
For me with this 21 million supply of bitcoin, I think it is really hard to be end and will never be shortage because of some big whales are more on hodl, with their great knowledge in manipulating bitcoin market by investing it in proportional in balance. Because big whales are the main character that moves bitcoin market to become progressive and more stable.