If Societe Generale Bank really want to using the Ethereum network and issuing a new token for their architecture,
the Ethereum value maybe only rise slightly. I think the more peoples and companies using cryptocurrency, the more value it will have.
That is one hell of a big bank there and I think they have their branches in virtually all francophone countries, there adoption of ethereum to run their blockchain technology will really expose a lot of its users to ethereum network, and their product may require the use of ethereum token from time to time for their operation.
So I think this will really be a very big boost to the ethereum network, the magnitude of this bank customer is quite big, and most of them are very rich individuals that have enough money to be a BULL when they decide to join the ethereum network through the banks product.