How to predict trend of HSI?

恆生指數是一個市值加權平均指數，而美國道瓊斯指數則是股價平均指數。市值加權平均指數與股價平均指數又有何分別？以道瓊斯指數為例，成分股共有三十隻。計算道瓊斯指數，是首先定出一個基點日，將三十隻成分股的基點日股價加起來；然後，再把成分股現在股價加起來除以基點日的股價總和，就可得出指數。這種平均股價指數的方法好處在於簡單，易計易明，但卻忽略了公司規模及市值的影響。恆生指數所採用的是市值加權平均法，在計算成分股股價總和之時，先乘以股份佔恆生指數總市值的百分比，再計算出指數；所以，市值較大的股份如匯豐（0005）及和黃（0013）等，它們股價的升跌便對指數有較大的影響，但指數卻更能反映市場實況。

The answer compresensively explains HSI AND Dow Jones Index but slightly deviates from the main point - How to predict the trend and not 'what are the defintions and advantages?'

There is no simple way to predict the future index, if there is, anyone can make money from the market. Maybe you can find something in HSI future.However, it is just a mixture of speculations.

Personally,I think technical indicators are not that useful. And if you are buying stocks,why cares about the HSI? You are buying companies,not the index.Preditions are not necessary in investment.When the index slumps, there are shares still rises, isn't it?So, chose several companies you think are excellent, buy and hold, wait for years, then, you will get a far more better results than those speculators.

P.S: The stock disaster is a perfect oppotunity to buy shares at reasonable prices.