Holding = guaranteed success. Period. Bitcoin isn't going anywhere but up.
Guaranteed? LOL.
You are being as silly as the "single digits in 2014" crowd.
Yes if you believe in bitcoin hodling is a guaranteed success. It has been since bitcoin was created and as long as more services are being built we're safe hodling.
If bitcoin goes down the shitter day traders will also have problems getting their fiat out of the exchanges like MtGox so not-hodling is equally risky maybe even more risky.
As stated by bittburger people who play the market eventually lose because they end up with worthless fiat or alt-coins when bitcoin skyrockets.
Only the few fortunate advanced traders will make a good buck daytrading but most people lose their shirt.
Bitcoins normal fluctuations can be up to 10-20% of it's value and as far as I know no exchanges do stop-loss or limit orders so limiting risk is near impossible and in my opinion there is no way a normal trader can do any good money management unless they have a shitload of money already.
My motivation:
When bitcoin skyrockets it goes so fast you might aswell board the train when it's stuck in the station instead of trying to boarding in the last second and missing it.