Eric Nuttal sold ATH & bought BTEI did the same some months back as stated in my previous comments.
I also bought back into ATH and both BTE & ATH have been on a tear.
If you listen to EN comments, he states " Optionality" and " volatility" and will likely buy back into ATH on a dip.
He simply moved profits over to BTE because it got beat down and now is ripping hire more than ATH.