Subject: Re: Fair value?
Unless my table missed something, 1.4796 times "peak to date" known book at start of the month of the buyback seems to be the absolute top ratio paid for a B share (again, average within the month--presumable a few shares a bit higher and lower).

Another quarter in support of your point -- the stock dipped down to the low $440s a couple times in Q4 and Jan 1 - Feb 10, but we have zero buybacks in that span.

If past A purchases were the best guide, we probably would have seen at least some repurchase activity -- the buy trigger would have been about $457 based on Q3 book. If the top ratio paid for B is the better guide, the trigger point was ~$432, which was never hit.

New B-guided trigger point would be around $445.