It’s Ninja Lesson time.
I am not sure if you have heard of the quote before

“Amateurs open the market, but professionals close it”.

 In short term trading, closing prices are more important than opening prices. It tells your the force behind the price movement and whether the price is weak or strong.
Who sets the opening price? Usually it will be people who have read the news (such as results or news announcement) the night before and then put in their orders early in the morning before market opens. 
Who sets the closing prices? Usually, it will be the professionals or market players who determine how and where the prices should close. They have their reasons for wanting to close the prices at a certain level and they usually come into the market nearer to its closing time. Which is why sometimes you see a spike in volume after 4pm …