The market went down on Monday and Tuesday, then came back on Wednesday and Thursday, only to fell again, slightly, on Friday.
Don't bother to look for some rational explanations, you know they won't make sense because whatever reasons offered for Monday and Tuesday's declines would have to be reversed, only 2 days later ...
The learning? The market is full of noises in the short term, as an investor, you need to focus on the long term market trend.