I can now see why the stock went down and coming back again.
VBS Exchange was 6.275% holder before, now 7.775% holder. Bought ~23m shares more.
Bought 6,538,412 shares in less than 1 month from 24 April to May 22.
~3.5m of it was bought starting at the bottom (6.5c) until yesterday.
Good timing for a substantial holder to buy more.