my doubt is when those big banks gets in, what will happen?  a new coin? or just pump the bitcoin again

Banking giant JPMorgan Chase has filed a patent application for an electronic commerce system that sounds remarkably like Bitcoin — but never mentions the controversial, Internet-only currency. The patent application was filed in early August but made publicly available only at the end of November; it describes a 'method and system for processing Internet payments using the electronic funds transfer network.' The system would allow people to pay bills anonymously over the Internet through an electronic transfer of funds — just like Bitcoin. It would allow for micropayments without processing fees — just like bitcoin. And it could kill off wire transfers through companies like Western Union — just like Bitcoin. There are 18,126 words in the patent application. 'Bitcoin' is not one of them.