Subject: Re: A to B ratio
Could the Bs being in the S&P 500 be part of this?

It doesn't seem so--they have been in the index for some years now, and the ratio was pegged extremely close to 1500:1 for the first few years after that.
In fact, it was closer to 1500 after the index inclusion than it was years previously. The "old normal" for a long time (prior to the credit crunch, say) was about 1502.

Jim