Building Wealth

Is it safer to keep cash in a local community bank or an Vanguard money market if could only pick one? I'm trying to ascertain the safety of holding money in Vanguard. One thing is, you need excellence. So when people say small versus large to me, my question is are you talking about large excellent and small excellent or small, horrible and large excellent? In other words, you have to do diligence each institution one at a time.