That's because float has gotten so low. I remember last runup, which was not fueled by news, we used to get some 20MM shares daily average. It's either buyback shrank the float, or someone accumulated all the float there is.
The CEO said he has begun buying shares back in the last 2 months so far 15 million shares if I am correct. Do some DD. Or email him yoursef. Did you even look at todays daily ANTS shorts? Over 45% shorted.