"It is quite the amazing trend line, and I have done similar ones myself. There is no observable slow down in observable value generation since the Gen Re acquisition in 1998."

BV growth over time is indeed amazing, in both its rate and its consistency. If you haven't already done so, try plotting BV/share back to fiscal year-end 1964. You'll see two, distinct knees in the semi-log plot, one in late 1980 and one in late 1999, with straight line (semi-log) growth in between. The rates of growth in the three resulting periods are: 18.6%/year from Oct 1964 to Dec 1980, 28.8%/yr from Dec 1980 to Dec 1999 and 10.5%/yr from Dec 1999 to Jun 2024.

Price/share tracks BV/share. The log-log plot of Price/share versus BV/share is a straight line with an extremely good fit, with no discontinuities at the points where the semi-log plot of BV versus time has knees.

In summary, BV growth is quite consistent from 1964 to 1980, from 1980 to 1999 and from 1999 to 2024, but with different growth rates (semi-log slopes) in the three different periods. Price tracks BV across all three periods of BV growth from 1964 to 2024, in a single (no knees), straight line with extremely good fit.

PS. I have argued that the trendline of the log-log plot of Price versus BV provides a good estimate of IV at any point along the curve, as long as the time period covered is long (>30 years). "In the long run the market is a weighing machine."