I just posted a new topic about getting historical IV for Berkshire, and did so not having seen @cwags02 and @johnIII posts just about the same time that I posted.
In my post I asked if people have a time series for IV (not book).
What prompted my question is that my Morningstar data goes back to 1991.
I’ve done a somewhat similar analysis to @cwags02 with that longer history data, and things start to fall apart.
In tracking down ‘why??!’, one obvious glitch is the huge jump in book, and hence fall in P/Book that occurred in last quarter of 1998. So, what’s up wiith that?
From the 1998 annual report:
"
Our gain in net worth during 1998 was $25.9 billion, which increased the per-share book value of both our Class A and Class B stock by 48.3%. Over the last 34 years (that is, since present management took over) per-share book value has grown from $19 to $37,801, a rate of 24.7% compounded annually.
Normally, a gain of 48.3% would call for handsprings – but not this year. Remember Wagner, whose music has been described as better than it sounds? Well, Berkshire’s progress in 1998 – though more than satisfactory – was not as good as it looks. That’s because most of that 48.3% gain came from our issuing shares in acquisitions.
To explain: Our stock sells at a large premium over book value, which means that any issuing of shares we do – whether for cash or as consideration in a merger – instantly increases our per-share book-value figure, even though we’ve earned not a dime. What happens is that we get more per-share book value in such transactions than we give up. These transactions, however, do not deliver us any immediate gain in per-share intrinsic value, because in this respect what we give and what we get are roughly equal. And, as Charlie Munger, Berkshire’s Vice Chairman and my partner, and I can’t tell you too often (though you may feel that we try), it’s the per-share gain in intrinsic value that counts rather than the per-share gain in book value.
"
Ideally, we should be using IntrinsicValue not BookValue.
Or, perhaps someone with skills in fundametnal analysis has a suggestion about how to simply rejigger book?
Anyway, one lesson learned is that you should always the plot the time series of interest.
Look for any dislocations, then go back to the annual reports to see if they were related to corporate events.