Subject: Re: Back of the envelope
I updated my Grove model.

All actual Q3 numbers except Grove #1 - Operating earnings. I used previous year earnings plus 10% growth. I also use a $30 BB deduction from cash for reserves.

I get a value of around $475.

I did mine, FWIW.
Same $30 BB deduction from cash.
Used actual op earnings, rolling 4 qtrs, 15x
Insurance underwriting earnings, rolling 4 qtrs, 10x
Deductions for taxes due on equities if sold.

Estimated IV $444

I've noted that I always get a somewhat lower value than you.

I'll redo my look-thru when the holdings come out. Funnily enough, it's likely to be higher due to a higher earnings yield on cash vs Apple!