Slow rise means stability around that price so people can consider it as a buying rate if they want to take the risk to buy at that rate. And I agree with your last statement, don't just hold and hold as it will just take you for another round of holding resulting for more other days or even months of waiting. Just take part of every price rally to earn more when selling and to accumulate more when buying.
yeah trading allows us to make regular profits and I think we should take best advantage of price fluctuations and keep on growing our coins regularly.
There is always an opportunity to make money in trading and if you are good in it then you can expect regular profits and you should also sell your coins when price is higher.
That's true to make profit by selling bitcoin when one think that the price is high. Rather than this its better to have close observation upon the price movement and decide selling when you're close to the expected price of selling.