Just some personal observations about the effects of Berkshire´s wild swings in price:

Though I promised to myself after it reached $470 and selling some to never ever sell another share (then 60%of net assets), at $520/$530/$540 every time I became weak again, with Berkshire now down to 40% of net assets, the lowest ever.

Cash from the proceeds kept up piling as I didn't know what to do with it. Additionally from gains from puts I regularly bought and sold while Berkshire moved up and down between $520-$550. A huge bet, with at the top puts having been 10% of net assets, which worked out superb. Having as half as much puts now the situation is "balanced": When Berkshire goes down the loss in share value and the gain in puts value effectively cancel each other out (The value of the puts is around 1/6 of the shares, and if Berkshire falls 1% the puts go up 7%-8%).

What's new: That I have a hunch this year the day will come when I can put my cash to work again --- by buying Berkshire shares. Under $450 I will start accumulating. I didn't update my Price/PeakBV chart since a long time but think a 1.4x PeakBV is somewhere around that price?