Ethereum Co-founder Vitalik Buterin has proposed an Ethereum improvement proposal (EIP) on the amount of Ether that can be created of ~120 million.
This recent proposal can be found on the developer’s forum Github post from April 1st. Buterin feels the hard cap for ETH needs to be at a maximum supply of 120,204,432, which is two times the amount of ETH sold in the original Ether sale. This action, if taken, would most likely occur by the first phase of the Casper update.
“For ensuring the economic sustainability of the platform under the widest possible variety of circumstances, and because issuing new coins to proof of work miners is no longer an effective way of promoting an egalitarian coin distribution or any other significant policy goal. I propose that we agree on a hard cap for the total quantity of ETH.”
If this EIP is to be implemented, staking and mining rewards along with staking interest in the sharing system will need to be redenominated.
Buterin says that if for some reason the EIP was adopted at a point where it was too late to set the ~120 million max cap, that he would recommend a cap of exactly 144,052,828. That number is exactly 2 times the total amount released in the genesis block, including both the sale and premines.
There are ~ 98.5 million Ether currently in circulation.