Ethereum will experience several hard forks, 3 of which are most significant:
1)Classic Vision Hard Fork – 11 Jan 2019: All Ethereum holders will receive 3 ETCV for each ETH in their wallets.
2)Ethereum Nowa Fork – 12 Jan 2019: Each ETH holder receives ETN in the ratio of 1:1 for free.
3)Constantinople Fork – 16 Jan 2019 (or earlier) Constantinople Mainnet hard fork scheduled for block #7080000: The Constantinople Mainnet hard fork is arguably the most significant fork because it is a big component of Ethereum’s transition from using a proof of work protocol to proof of stake
https://ethereumworldnews.com/okex-to-support-the-upcoming-ethereum-eth-constantinople-hard-fork/