A shares dipped below B shares today

[aws]

I was buying some BRK.B right before the close today and ended up watching something weird happen after hours.  Normally I don't think Berkshire trades at all in AH, but it started trading pretty heavily and was down almost 1% on over 1 million shares of volume.  I spent like 10 minutes looking for some type of press release because I was curious what was causing the stock to move. 

 

I think I just figured it out though.  The last print on B shares was 129.10 but on A shares it was 192,200. 1/1500th of that is 128.13, meaning A shares could be converted at a profit to B shares.  I'm not sure how often that happens but it caused both B and A shares to have a lot of after hours activity.  I wonder if any humans were involved in those trades or if it was a flash crash type situation.

[karthikpm]

Warren Buffett talks about this on BRK's website

 

http://berkshirehathaway.com/compab.pdf