Need to do some DD on this. Berkshire continues to own 10 million shares as of 9/30, reported 11/15. Next report date would be Feb. 15th. I'm a big fan of Brazilian companies, I know there's "political risk" in Brazil, kind of like China, but it's overblown IMO.
Looking at a bottom around 14-15, noticing higher lows, now just need to see prices higher than 21 for a confirmed uptrend. Note that 21 is 50% more than 14; this is probably why I'm into bottom fishing, I don't want to miss a big price rise, in exchange for a lower win rate.
Trade this however you want, I have no position yet, just posting for interest.