NETWORK UPGRADE
We understand that there is a network upgrade coming up by mid-January called "Constantinople", this is to handle the many flaws of the ethereum network, ranging from slow confirmation time, high fee and numbers of transactions per seconds/scalability.
HARDFORK
There is another rumor that a hardfork will take place by 11th of January 2019, which will create a new coin and every ETH holders will receive 3ETCV(Ethereume classic Vision). 1:3. 1ETH=3ETCV. For example, if you have 100ETH in your private wallet you have the private key to, you will receive 300ETCV. So am just wondering if ETH will fall after the upgrade and fork or just keep rising. You can check the Hardfork ANN thread here: https://bitcointalksearch.org/topic/ann-etcv-ethereum-classic-vision-fork-31-of-ethereum-5089443
First time I hear about this "3ETCV"-Hardfork - however most people know about the official Constantinople hard fork which will happen at Block 7.080.000 (between January 14 and January 18) but it won't result in a new cryptocurrency - it's just an "upgrade" and another step on the Ethereum roadmap.
Progress Tracker: https://github.com/ethereum/pm/wiki/Constantinople-Progress-Tracker
Changes:
https://eips.ethereum.org/EIPS/eip-145
https://eips.ethereum.org/EIPS/eip-1014
https://eips.ethereum.org/EIPS/eip-1052
https://eips.ethereum.org/EIPS/eip-1283
https://eips.ethereum.org/EIPS/eip-1234
And I doubt that the "3ETCV" hard fork will have any noticeable effect on the ETH-price.