Anyone who wants to venture into bitcoin should look at the long run, one should know it's an investment and investments are for the future, you shouldn't be bothered about the current price of bitcoin if u want to invest and targeting to make reasonable profit out of your investment because bitcoin definitely has a great potential for the future. We have seen how it has grown from nothing to the price it's now and it won't even stop rising so everyone should just target the future.
If you're a bitcoin trader that buys when the price drops and sell when it rises you should also be able to make long term plans too you can buy and sell, you should also buy to hold too because no one can predict the market.
Buying and selling of bitcoin is not the Better way to go about bitcoin investment because you might sell at lost, bitcoin investment is a long time you can start buying bitcoin using the dca strategy and hodl for 4-10 using your discretionary Income, as a new investor you shouldn't think of selling your bitcoin instead your main focus is how you should be able to buy stack more bitcoin.
Those who buy and sell bitcoin are traders and not investors and investor will reap from his long time investment because his bought good size of bitcoin to his portfolio while trader will run at big loss.
If I understood what Big_ panda is saying, I think he is suggesting diversification of having a trading account and investment account in Bitcoin that is where he saying that those buying and selling Bitcoin for short term should also be buying and holding for long term, on this note I will say if at all anyone will be considering diversification in their ongoing Bitcoin investment, it will be better they look out for anything not related to Bitcoin, and it will be more better than investing in Bitcoin and at the same time being a Bitcoin trader, trading Bitcoin can be time consuming and can lead to vulnerability of impulsive decision making, focusing solely on Bitcoin investment will be more better than being a trader and at the time being an investor because investing is less stressful.