"BV per share remains a very good indicator of IV per share."

If we plot Berkshire's price/share from 1965 to present (semi-log), we see, of course, that it has increased substantially, from $16/share to $459K/share. If we plot Berkshire's BV/share from 1965 to present (semi-log), we see that it has also increased substantially, from $19/share to $310K/share. If we now plot price/share versus BV/share (log-log), we get a straight line with a remarkably good fit (power law). The trendline of the plot represents a decent estimate of what the market is willing to pay for a given level of BV/share. I contend that the trendline also represents a reasonable estimate of IV. This IV estimate agrees well with IV estimates by other methods.