Hmm, a good strategy in the first post, but I think that in this case it is possible to improvise. So, for example, if the price of bitcoin has risen very much, you can not buy It at all. On the contrary, if the price has fallen significantly, you can buy Bitcoin with all your money. It all depends on the specific market situation, news, etc.
I think there are still several methods for safe and comfortable trading, one of which is implementing long-term trading in bitcoin, why only bitcoin? because in my opinion bitcoin has a very high demand but has a limited supply and it's very difficult to get bitcoin so take advantage of bitcoin for long-term trading and safer trading.