Taking profits is okay, but is not necessarily the thing to do in all cases.

There are a couple of problems with taking the profits:   1.  It generates income tax   2.  When you pull the money out of a good stock, where are you going to put it next?  You have to put it someplace, and once you have invested in the markets and made money, you are not likely to put it back in a savings account at the bank!  So you end up reinvesting it in another stock (probably) - now it becomes a question of whether the new stock is a better place or safer place than the original holding.  

If you are in a solid, high potential stock in the first place, it might be just as well to leave it there and not pay income tax.  

However, having said this, the other side of the argument is that taking a profit and redeploying the funds elsewhere can add diversification and perhaps a bit of security against a fallback (again, depending on where it is reinvested). 

Lion