I have been asked by my friends regarding this issue occasionally and before answering the question I would seek for their own idea and then only tell them my opinion, most of the answer provided are "only possible by luck" , insider new and so on. Personally, I think it is possible to buy low and sell high but it is impossible to "buy lowest and sell highest". Those who try to find out the lowest and highest price will probably end up losing a huge part of their capital.

How?
One crucial element to be able buy low and sell high is PATIENCE.
Let us say the price of EUR/USD has made new low/lowest at $1.2240 and bounce back to $1.2340 indicating uptrend is coming and it is advisable to long the currency pair at $1.2340 and forgo 100 pips profit. One should wait until the price confirm that the currency pair is going up again in future. One should not long the currency pair at $1.2240 as there is no indication that the pair is going to reverse its trend.

So, one must possess PATIENCE to wait for the "right price" and willing to forgo some minor profit in order to increase the certainty of trend.
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