Nothing nefarious. Companies have a couple of business days to disclose becoming a substantial holder (http://download.asic.gov.au/media/1241414/rg222-issued-15-april-2011.pdf), although they seem to take longer.
If you look at the date on the notice it was 2nd June.
If you look at the date on the previous ceasing notice it was 1st June.
They are flirting on the edges of 5% so can go up and down quite easily.
Whatever happened today won't be known for a few days.
VOC Price at posting:
$3.48 Sentiment: Hold Disclosure: Held