Some investors have a strict diversification discipline, and refuse to let any stock -- let alone a pink sheet stock touting a Niger / China $200 million deal -- constitute more than a certain percentage of their investment portfolio. If you took a sizeable position at $.015, it is now a much bigger % of your total holdings than it was when you bought it.
There is never anything wrong with taking profits. Some investors have had rough experiences with "life changing," "can't miss", "to da moon" stocks. Of course, we all know that AMMX is different. . . .