*Source from bloomberg
This table consolidates the % drop in price of the present STI components as relative to the past 2 economic crisis.
As you can see..in general most of the stocks price have not reach their historical % drop in price. The only two have the historical biggest drop is SembCorp Marine Ltd and Cosco Corp Singapore Ltd which are shipping companies.
This is to give you a rough guide of how much you MIGHT want to wait before you start buying certain sectors. It is true that historical records does not mean it will happen again in the future, but it still serves as a rough guide.
If you are worried about picking the wrong industry, you can invest in the STI ETF. Which is basically a fund that tracks the STI index..which also happens to contain most of the blue chips in Singapore.
However they are 2 kinds of STI ETI. One is the DBS STI ETF 100, the other is the 'normal' STI ETF. There are some pros and cons to each of them. And I suggest you read them up before investing in them. Some factors to consider is the lots size, managment fee ( yup, you have to pay the managers who have to manage this ETF!) etc.
Here is a link to some comparison of the 2 ETFs : http://www.moneytalk.sg/2009/02/dbs-issuing-sti-etf.html