Price-to-last-known-book 1.724.
... In any case, I think the momentum boys have climbed on board for a little while, Berkshire is now rallying even a bit more than other insurers.

Well, crap! BRK is my largest holding, but that P/B is *really* high, historically.
According to financecharts.com - Price to book value the highest was 1.82 at Dec 2007.
Next highest was 1.64.
Ycharts shows it is currently at the 5 year high. (5 years is the most you can get without subscribing.)

I would be afraid that a covered call would play me for a fool like it did last time. Not a whole lot of money, either. The Oct 500 call is only 4.65 with BRK-B at 478.

At 500 the P/B would be 1.79. Possible.

what to do, what to do, what to do?
Trailing stop? Covered call?
Of course, "nothing" is always an option.

Berkshire is now rallying even a bit more than other insurers.

Dealraker made a post on 9/1/23 where he talked about AJG and BRO and insurance being "an absolutely fantastic business".
On 9/13/23, "I've been hyping the insurance brokers AJG and BRO for 25 plus years."

A post on 12/19/22 quoting Buffett, "We should have gone into the insurance brokerage business instead of underwriting" where he mentioned AJG and ERIE.

Sorry for the rambling. This BRK action has got me at sixes and sevens.