Holding is one of the best thing you can do right now because the bitcoin is gonna rise, what is already mentioned here in the above topic.
I really think there is a good chance that bitcoin is going to a higher amount.
Holding is quite a selfish thing to do, though. If you circulate bitcoins around (instead of freezing a small amount of the market) you'll spread demand more, and it could also potentially allow for more awareness in the bitcoin community. That, in turn, could bring forth more people to bitcoin, which would increase demand and slowly drive the price upward. Though you can hold, you should also remember to spend at least some thereof.
If everyone held their coins until the end of time, where would the demand go?