Hello, my question is about an imbalance in bid/ask price. I noticed that in case of a rising put (last price) the bid price falls and the ask price increases . The put had from the beginning a spread of 2 Dollars. But the opposite movement of ask to bid price is very strange. I refer to the puts of APLS. ASK price: 7.50, Bid price: 11.70; Last: 9.70
Low volume/low liquidity underlyings do that; wide spreads that get even wider with vol (read "uncertainty".) That's not an imbalance - just the market, or the market maker, saying "I don't have any idea where this crap is going to go, so you'll have to pay me to make a 2-sided market in it."
With lack of detail provided (Expiration, strike, when you are referring to, etc) it is likely that responses to the post will only be "guesses". So, my guess is: with lack of liquidity, movement in the BID and ASK prices may appear odd. {Are you referring to the 17SEP21 55 strike? ".APLS210917P55"}