Ignoring risk

Today STI is down a bit. Last week, we still see people much enthusiastic about buying and pushing up share. Just a week's time, the sentiment has changed a bit.
However, certain China play still keep going up after the quarter result announcement. Analyst keep calling a buy pegging the share at 24x of FY08 earning etc. It looks to me, the possibility of going further up is limited, but the downside risk is greater. Let's assume China bubble burst suddenly, people would pull out from the rich valued share to cash. Assume you bought the stock at its peak, what is left to you is the short term paper loss. Furthermore, do we really can see into the future? If the thing does not really turn out well as it should be. There are just too many similiar cases before, beware!