Below are the dates, average purchase prices and approximate P/B for Warren’s stock repurchases, which began in October, 2018. From Oct, 2018 to March, 2020 Warren dave us the dates during the month during which he repurchased; from May, 2020 to June, 2022 he gave us the months during the quarter during which he repurchased. By interpolating the book value/share between the start of the quarter and the end of the quarter we can estimate the book value/share at the time of purchase to within 1% (Book value generally changes about 9% to 10% per year, or about 0.8% per month). Prior to Q2, 2022 we only knew the prices that Warren would pay, but we had a less precise idea of the prices that he would not pay. In April and May of 2022, Warren paused repurchases, and it wasn’t because he needed cash to buy other stocks. He didn’t buy very much stock during the quarter. As we can see from the data below, the highest P/B that Warren has been willing to pay is 1.40, which, coupled with his statement that he will not buy above 95% of IV, leads me to infer that Warren’s estimate of IV/BV is pretty close to 1.5.
By the way, some people inferred the same thing several years ago when Warren gave an example in the annual report of a hypothetical company that had an IV/BV of 1.5, but that was reading a lot into Warren’s words. I think his repurchase prices are a much stronger indication of what Warren’s estimate of IV is. I think of it as the repurchase price IV model. An IV equal to 1.5x BV is also about the average estimate of the numerous people who have posted or published IV estimates, based on multiple IV models. I wouldn’t argue with someone who concluded the IV equaled 1.35x BV or 1.65x BV, but 1.5x BV seems to be the general consensus, even for Warren if I infer correctly from his repurchase prices. FWIW.
date, average price, approx. P/B at time
Oct 11-Oct 18 2018, $311K (Lowest price on 10/18 was $314K.), 1.36 (1.37 on 10/11)
Dec 13-Dec 24 2018, $296K, 1.39 (1.32 on Dec 24)
Feb 26-Feb 28 2019, $303K, 1.32
March 1-Mar 29 2019, $304K, 1.30
Apr 1-Apr 10 2019, $306K, 1.34
Jun 3-Jun 26 2019, $311K (Lowest price on Jun 26 was $310K.), 1.33 (1.32 on Jun 26)
Aug 5-Aug 28 2019, $300K, 1.25
Sept 3-Sept 30 2019, $310K, 1.27
Oct 1-Oct 9 2019, $306K, 1.26
Nov 11-Nov 29 2019, $329K, 1.31
Dec 2-Dec 31 2019, $333K, 1.29
Jan 3-Jan 15 2020, $339K, 1.30
Feb 24-Feb 28 2020, $325K, 1.32
Mar 2-Mar 10 2020, $301K, 1.31
May 2020, $263K, 1.11
Jun 2020, $269K, 1.09
Jul 2020, $281K, 1.14
Aug 2020, $317K, 1.24
Sept 2020, $325K, 1.23
Oct 2020, $316K, 1.21
Nov 2020, $341K, 1.21
Dec 2020, $343K, 1.21
Jan 2021, $348K, 1.21
Feb 2021, $363K, 1.25
Mar 2021, $396K, 1.35
April 2021, $408K, 1.39
May 2021, $433K, 1.39
Jun 2021, $432K, 1.39
Jul 2021, $420K, 1.33
Aug 2021, $431K, 1.27
Sept 2021, $419K, 1.27
Oct 2021, $432K, 1.37
Nov 2021, $430K, 1.31
Dec 2021, $440K, 1.28
Jan 2022, $456K, 1.33
Feb 2022, $474K, 1.38
Mar 2022, $485K, 1.40
Jun 2022, $426K, 1.36