Trade on News

In my early days I used to trade on news. However more often than not it ended badly.
After several rounds of lesson fee to the market, I came to realise why.
There are primarily two reasons.
1) Because market is often forward looking. When the news came out, the negativity or positivity of it would have largely been priced in.
2) Secondly and this is related to reason 1, is that the insiders or big boys would use the chance to take profit when the news is released to the public, hence leaving those who bought at the news "trapped".
There are some specific kind of news which traders and investors can make use of for example earning release and inclusion into indices.
For the former, I find that the guided outlook is often more important than the actual reported earnings in terms of short term share price effect.
For the latter, inclusion into indices is normally a good news as funds have to rebalance their portfolio for the new inclusion and this usually has a positive effect on the share price of the included counter.