Long term investment is simply about following the trend of economic growth. I am not convinced there is much more to it that that.
Futures traders generally employ exit points in the form of volatility based stops for each position (established at initiation) determining when to cut a loss short and operating in conjunction with position sizing rules.
A quantitative trend following system must define: when to enter a position; how much to buy; when to exit a position.
The Global Macro hedge fund strategy can be defined as dynamic global asset allocation. Global Macro hedge fund managers have the ability to take positions in any instrument in any market throughout the world.