Does anyone else find it highly suspicious that Coinbase goes down whenever there is any major movement in prices?

You can explain this as just the natural result of too much traffic, but that's not convincing. This is a business valued at over 1 billion dollars that has been operating for years. If this is still a problem, it's either unbelievable incompetence, or because they see no reason to fix it.

And here is a worst-case theory, by way of speculation not accusation. Being down whenever there is a lot of movement lets them beat all of their customers. When there is a crash, they can sell before their customers can. When there is a boom, they can buy before before their customers can. And because such a big portion of the market trades through them, this is more than trivial gains.

I have no way of knowing if this is what's happening, but it seems to be worthy of discussion, given how many people are placing trust in them. They don't really have an adequate explanation for the constant downtime, and I think they owe one to their customers.