I have a feeling there are also trading bots on IMX market. Not everywhere, but only about some cards selling for GODS. I was obsessed by buying and selling cards and watching things closely last 3 weeks. I did 381 trades during this time :)
And I have noticed you can try selling a cards for many days without result because, in a minute or two after you post a card on the market, two other (previously cheapest) cards slightly change their price to stand before you. First, I thought it was a real person, a stubborn and insane one like me :), but no this is not possible. 1stly, I wake up and go to sleep at a quite random time and this is strange that I encounter these things at any time of the day. 2ndly, there was a pattern about changing prices - a real person wouldn't repeat the same price change every time. 3rdly, price changes endlessly. What to do? Sell your card for ETH, not GODS. I believe someone was buying for ETH and selling for GODS and decided to develop the super profitable business by means of using a bot... It is fine but such bots can make the market dead.
Would be good to have a way to report such things. I would even explore things through immutascan.io, it can be just one person with a program... But I don't want to waste my time since, most probably, I won't able to reach GU devs with this info and nothing would change.