Because it's small, there is closer bond between me and my colleagues. Everyone knows each other. The organization is very flat where employees of all ranks get along. When you want to get things done, it'll be easier.
BNP Paribas is a well-established name that other employers recognises. This will be good for CV for my future job application. Company has a smooth workflow and information flow. Lastly, company makes effort to be transparent about the things happening in the company for example by sending out newsletters