I've never held Bitcoin in the long run. I always sell it when I need money or to buy Altcoins. And I'll buy it again when I see the market turn red. At least, I can still continue to profit from holding Bitcoin in the short and long term. And don't forget that mentality affects decisions when trading.
That is how to reduce the losses that may come in the up and down of the price. Besides that, as you say, you can make a profit from doing that repeatedly, so that can be the way to make money. We need to sell bitcoin at the highest price, so we can buy back again when the price is down or drop deeper because after the price touch the highest price, it will go down for correction. That will be the best time to buy back bitcoin again, and we only need to wait for the increases in the price.