This is debatable on strictly objective statistical grounds. It is not given that Bitcoin will grow in the future and won't collapse to lower hundreds at the end of the day. So just keeping bitcoins offline doesn't make the Bitcoin investment free of risk altogether. On the other hand, the growth of Bitcoin is never linear. I mean that today's price is not always higher than or equal to yesterday's. Corrections do happen, and the higher the price rises, the deeper and thicker they will become...
In this way, the least risk mode of investing in Bitcoin would certainly not be dumb holding but holding with a little bit of selling and buying now and then
I meant to say that compared to all other investment options, just holding your coins is the best/safest possible investment. This however doesn't mean you need to keep holding everything firmly without securing profits every now and then. It's up to the person. I personally have one stash that I don't, and won't touch in the coming years, and a stash that I use for trading purposes. This way I make profit all the way, and my long term holding coins stay exactly where they are
Okay, I see what you mean. In this way, just holding coins taken separately from other investment options available for Bitcoin (including investing in Bitcoin itself) may well be the safest option. Regarding your particular case of managing coins, I'm not very far from it myself. With the only considerable difference being that I keep growing my reserves of bitcoins which roughly correspond to your "untouchable" stash of bitcoins. Really, if you are trading profitably with your working capital, sooner or later it will surpass that stash...
Then why not add more coins to it, just to keep balance and not lose future profits?