My strategy is to buy low and sell high, like any other. But not only Bitcoin, also any other criptocurrency (Altcoins).
What often happened to me, was that I bought a coin, the price was rising and then, i sold it, but after a few days that coin, was continuing rising, and that made me angry, then instead of selling it all, now i sell 75% of what I bought, thus obtaining a minimum gain of 25%. and keep the other 25% by doubts whether the price increases.
What I always recommend, is to diversify your earnings.
Good Luck!
your strategy was the basic strategy in growing bitcoins , but im not saying that it's bad
maybe try some other experiment for your bitcoin and do other bitcoin business try to use google.