Discussed a number of times before.

This is not an estimate of fair value, merely a number intended to rise at the same rate as true intrinsic value. Think of it as an attempt at true value per share, times some unknown constant not too wildly far from 1.
Investments per share, less a penalty proportional to float for the perpetual drag from having a cash-heavy portfolio, plus a multiple of trailing-four-quarters net income from operating subsidiaries, plus a cyclically adjusted estimate of underwriting profit in lieu of the recent figure. Highly valued equities are valued at a 21 times earnings, not market value, but never less than half market value.

All figures in June 2026 dollars with CPI 332.568

One year rate of change of this metric: Inflation + 7.77%
Three year: Inflation + 6.70%
Seven year: Inflation + 6.35% (pre-pandemic baseline)

In short, the rate of growth this metric hasn't done as well as a multiple of book value because investments have done well lately, but operating earnings have not.

2012       271688
2012.25    285047
2012.5     290643
2012.75    296275
2013       315511
2013.25    315307
2013.5     325231
2013.75    335546
2014       340719
2014.25    345016
2014.5     351596
2014.75    355922
2015       359785
2015.25    339848
2015.5     341030
2015.75    354859
2016       369322
2016.25    383203
2016.5     390162
2016.75    390768
2017       403313
2017.25    407877
2017.5     425265
2017.75    451588
2018       446483
2018.25    465948
2018.5     474106
2018.75    487364
2019       515241
2019.25    466815
2019.5     477963
2019.75    486162
2020       529138
2020.25    559061
2020.5     601583
2020.75    621614
2021       622948
2021.25    629819
2021.5     602134
2021.75    585748
2022       608951
2022.25    582911
2022.5     600309
2022.75    572309
2023       603111
2023.25    615477
2023.5     627174
2023.75    650704
2024       657335
2024.25    658479
2024.5     676696
2024.75    698350
2025       702836
2025.25    706947
2025.5     729298

Based on ~20-year historical relationships between market price and various valuation metrics (this, book/share, whatever), I'd expect a market price in the $440-490 range now, my best model putting it in the low $460s. Of course, there is no reason that the future average multiples have to match the past average multiples, but if they did, then that's the rough price range you'd expect. Phrased another way, the price a year and a half from now might be anything, but if one had to guess, maybe it's a 50/50 chance of better or worse than "flat in real terms".

Jim