t it is NOT limited by supply.
It doesn't have a hard coded limit, but the block time increases faster than the rewards.
"So here is a thought. Currently, because of the PoW ice age, the block time is scheduled to start increasing in mid-2017, and past around 2019 the increase is going to grow exponentially. The mining reward does NOT increase proportionately. Hence, there is already an exponential slowdown in the growth of the ETH supply built into the protocol; my script shows:
Block 3000000, approx ETH supply 87962556, time '2017-01-16 00:38:33.067775' blocktime 14.86
Block 3500000, approx ETH supply 90612556, time '2017-04-11 18:09:34.273529' blocktime 15.27
Block 4000000, approx ETH supply 93262556, time '2017-08-15 18:20:24.642729' blocktime 30.01
Block 4500000, approx ETH supply 95912556, time '2018-11-03 05:55:48.912370' blocktime 136.71
Block 5000000, approx ETH supply 98562556, time '2025-10-02 11:47:30.658317' blocktime 835.81
Block 5500000, approx ETH supply 101212556, time '2128-03-20 09:14:16.483692' blocktime 17183.83
Block 6000000, approx ETH supply 103862556, time '5189-09-26 20:57:59.367004' blocktime 520901.19
Hence, in the foreseeable future, the supply will not go far above 100 million."
https://www.reddit.com/r/ethereum/comments/5izcf5/comment/dbc66rdLook closely how many years there are between 98 million and 104 million Ether.