Why can Destabilising Speculation and Asset Price Bubbles be seen as a Danger Sign for the Economy?

-Speculation is the art of People buying Assets, and selling them at a Profit Later -They assume that an Increase in the Price means it will Continue Increasing in the Future. And this reinforces itself - as more people Buy it, the price will Continue Rising and Rising. -This create Asset Price Bubbles - the Price has Increased Beyond its True Value -When the Bubble Bursts, the Confidence of Consumers Vanishes. And then the selling occurs, where people will keep Selling and Selling in fear of that they'll lose money -This is seen in Property and Shares, and the effects of a Sudden Drop in the Price of Property can lead to a Downward Spiral, due to Confidence and the Wealth Effect Vanishing, and Consumers Saving Instead