What percentage of your BTC holdings are you trading on these kinds of swings? 100% of it, or some lower amount?
Best strategy is to never trade any of your bitcoin holdings.
Wait for a small dip. Don't be greedy, buy small part on margin. If price goes further down gradually increase your long position. If price goes up gradually take profit and covert your profit in bitcons. That's it, simple and effective.
In this above post, you are making a few statements that could be misconstrued, and maybe the strategy that you suggest is a sound strategy that works for you and could well work for a lot of other folks, but I would not characterize your approach as the "best strategy" because that seems to assume too much about the particulars of other folks.
First, you suggest to "never trade any of you bitcoin holdings," and that seems really problematic with a very volatile asset, such as bitcoin. There are quite a few ways to trade your bitcoin and in a way that allows bitcoin accumulation, and to lessen volatility risk, and sometimes, there are just pure profit arbitrage opportunities really great odds to sell and buy back and to accumulate more coins... So, "never" seems to be a very misleading concept.
Second, I am not opposed to the concept of buying on dips because I engaged in that practice for more than 2 years starting from November 2013, and we know that there has been a lot of "dips" since then, but I have never bought "on margin." When you say "on margin" are you suggesting to leverage? That is very dangerous and can be complicated to employ.
Third, when you say "if price goes up, gradually take profits" that means selling some of your bitcoins, no? There are a lot of regular folks who don't want to deal with margins or leverage, so your assertion that this method is "simple and effective" seems misleading to me. Maybe it is just me, and you can explain a bit more why it is so "simple and effective" when I am having difficulties understanding what you mean?