I would look closely at the recent rankings for their 'flagship' game Crazy Defence Heros (CDH).
CDH's rankings are currently lower than that of Crazy Kings (CK), the original game.
Crazy Kings rankings elevated for a short time during the release period of CDH but have returned to levels that they were before the release of Crazy Defence Heros.
AB1's own announcement made on 15/02/18 states that CK 'typically generates about A$90,000 per month' prior to the release of CDH. Given that its rankings have fallen back to where they typically sat prior to CDH it is reasonable to think that the revenue for that game has returned to approx. $90k a month.
Given that CDH's rankings are now lower that CKs it is reasonable to suggest (without guidance from AB1 to the contrary) that CDHs revenues have now fallen below $90k a month.
People might not like reading this but that is my thoughts on why the SP is falling. Some of the revenue predictions made by posters on here need to be significantly adjusted based on the most recent app ranking data posted by
@Medicated .
The SP jumped substantially on news of high revenue from this game and it is falling now due to the revenue stream from that game not appearing to be sustainable at the levels originally announced.
DYOR.