part luck

Stock picking is part science, part art, part luck, part intuition, and always uncertain - "not precisely knowing."

Sometime there is one big random event happened and can seriously alter the stock movement in the opposite direction e.g.

Noble's Vice Chairman Share Placement @ $3.10

This is just one random event happening and you are damn unlucky if you have just bought and so lucky if you have sold earlier.

So you either blame your star or thank your star if this happened to you.