Question about BB trading strategies

Hey,

This might be quite a silly question, but I was wondering whether BB traders are allowed to take advantage of 'statistical arbitrage' opportunities they see in the market?

Few points on this:

- I realize 'statistical arbitrage' is a fairly vague term that encompasses lots of things, but I hear about it a lot and it just leads me to wonder

- I know most BB traders are involved in market making, but I didn't know if there was a gray area with desks exempt from the Volker rule? (is it just gov't rates desks in this category? what about the swaption side of things?)

- I know I am conflating statistical arbitrage with prop trading, and I don't mean to do that

Thanks.