STI fell to low of 2962 on 18 Aug.

It has now risen from this low to near previous high. In fact, the index is about 100 points away from previous high.

Let's do a hypothetical question.
If STI is near to previous high, what will you do?
Will you:-

1. Buy some more
2. Sell into strength
3. Wait and see, if break above previous high, buy

Well, if your answer is 2 or 3, then the resistance by previous high would be a strong resistance where people might be using this chance to sell out in profit, or break even point ( as those who didn't sell would likely have sat through the fall and now wait to sell at break even).

Regardless of which choice, resistance at previous high is likely to be very strong.
On the indicator, MACD-H shows potential bearish divgerence while RSI and Stochastic move towards the overbought region.

Well, it might be better to put some money in pocket first (to secure part profit).