Property bubble occurs when a development has more speculators than actual buyers.
eg. Condo A - 200 units
Speculators/Investors have invested 150 units.
Genuine buyers/homestayers have bought only 50 units.
In conclusion, there are more speculators/investors than genuine homestayers.
These are the people who pushed up property prices due to unreal or speculated market demand by the big guns, and the genuine home buyers are the ones who suffer from higher prices and limited units.
Here, property bubble comes into play. There are times when property bubbles will burst.