Not having traded this stock I don't know the specifics, but it probably didn't go up yesterday b/c it didn't hit a certain amount of volume bought long (2 million probably needed long) so it was technically frozen till reset.
Today it went up a tick or two so people covered their shorts and also maybe freed up their money for the weekend plays which caused the higher % tick up.
The 17 million wasn't overridden yesterday. It technically never counted because the stock was for lack of a better term frozen because it didn't meet the long volume required.
Not a real world market where all trading moves an IPO....but IPOs in the real world also have their own restrictions on trading the first day so yknow