Subject: Re: Sold BRK Calls Got Assigned
" Now it looks to be trading around 402.20. If I just buy the stock back at today's price, my round trip will have gained me $6.26 per B share."

Good morning, are you an American ? Did this happen in a taxable account ? If the stock traded 1/2 above the strike that's enough to generate the stock being called and possible sold. Would you be selling the puts in a taxable account ? Good luck.