Short Piece by Ben Carlson of Ritholtz Wealth Management about possible reasons and triggers to sell some of your investments.
Source
Summary
you have two opportunities to be right and two opportunities to be wrong on every trade or investment — when you buy and when you sell.
Rebalancing back to target allocation weights is the simplest way to sell a little of what’s been working and buy a little of what hasn’t.
There are better opportunities available.
Targets have been met.
Your rules tell you to sell.
Circumstances have changed.
Now go read for yourself:
http://awealthofcommonsense.com/2017/08/when-to-sell-your-investments/