There are some situations in the investment world that result in considerable confusion and risk.
In particular, I am still trying to process the action that has surrounded KCG Holdings (NYSE: KCG) last week. The position appreciated considerably, but there is obviously not going to be any resolution to the matter unless if I wake up one day and a definitive merger agreement has been signed. If the initial proposal and subsequent due diligence cycle does not come to fruition, then there will likely not be any press to that effect and the stock price will drop.
There is a very real reason to hold on (the suggested merger price was lower than my estimate of its fair value), and a very real reason to not hold on (there will be no formal merger agreement). Also, there is no information at all whether this merger would succeed or not, nor any indications on timing.
So the solution was obvious. Sell half.
This is a perfect situation where doing half applies. The psychological advantage is that I don’t have to cry if there is a better price given to the company, nor do I have to cry if they trade lower (since I know where their fair value rests).