Because the pump that is being shown here is for 24 hours only. When we say volume has risen by 166% for 24 hours then it is in regards to a day before prices. The graph tells us that one day before this pump occurred the volume was down to 166%. The initial value was less than 166% than the current volume.

Its easy to pump that high because the value of the coin is already very less, plus the market of 2 M is almost nothing and can be manipulated with tiny factions like 700 bucks here.

Also, the circulating supply is very low here. This means with 700 bucks more demand was created while supply being less it pumped lot.