This is a system of Bitcoin. The Bitcoin prices go up and down, that is not a unique thing. This is the best time to sell Bitcoin and when it will go down so buy Bitcoin. This is the system of Bitcoin and cryptocurrencies.
Maybe the cycle of a normal market that you want to say related to up and down prices of Bitcoin and other coins.Buy a good thing to do when your analysis concludes that price opportunities will increase for some time ahead. Now it is still in good condition to buy because the opportunity for Bitcoin prices will increase large.
Anyway, Bitcoin prices are like a peak of mountains. Let's see that Bitcoin price goes down in October or not. 
Do not wait for an increase in October because if it does not happen, the opportunity to buy will be missed, but look forward to an increase in other months and in other years. This month the signal is still good for buying.