BREXIT with the upcoming seperation of Britian from the EU how will it affect other EU nations and the economy?

I think Britain was one of the biggest contributors to the EU. With other members scrambling to make up the loss, the US economy will be stronger, dollar-wise, but our overseas businesses will take some hits. I'm sure US overseas interests are (and probably have been) hurrying to adjust for the changes coming down the pike. I hope everyone is keeping an eye on their 401K's.