I have never understood the concept of "free carry". I can't...

I have never understood the concept of "free carry". I can't think of any sane reason to sell an asset you think will continue going up purely so you want to avoid the risk of a loss on the asset. Your position should always be determined by the risks and rewards of the asset at the time, not what you bought the asset for.

Having said this many of us are very overweight in MUS. I am at my absolute limit of what I can justify holding based on the fundementals. The more MUS rises the more overweight I become. At some point I need to rebalance my portfolio.