"a bubble waiting to burst"

[Odessa Dawn]

"Many analysts believe Hong Kong's property market is a bubble waiting to burst. To deflate it slowly, the government has introduced a series of increasingly stringent policies since November 2010. These have made it more expensive for investors to buy or flip homes for a quick profit."

More: World's most expensive parking places - CNN.com

Does a bubble waiting to burst mean ticking bomb?

[Rover_KE]

You've got the right idea, OD.

[englishlisteningworld]

Answer: Basically, yes that is a good comparison of expressions. The market is expected to deflate rapidly and suddenly without warning.

[Tdol]

When prices rise excessively and irrationally, you have a bubble, and this normally leads to a crash, so it is a ticking bomb, though possibly one that implodes.