For sure it will affect the Ethereum market but I think it will not last long, considering that there is a big development coming for Ethereum so I think it can recover easily. Also, I'm expecting that more investors will come in at the start of 2020 and it may give a big impact on the crypto market as well as for Ethereum.
It will last long caused by plustoken is holding a lot of ethereum and it's more than 800k ethereum. So many people have made their own prediction of the plustoken dump will not affect ethereum only but the whole of crypto consider plustoken has already raised more than 2 billions in form of the various assets.
That will bring a very bad impact to the price of ethereum and that needs more time for ether to recover its price caused by dump from plustoken.