I'm starting the first 10 shares approximately Wednesday. I agree that with this, as with anything, you will have to make a prediction about your expectation before making the investment. If you think the growth rate will stay large or increase more, it makes no sense. If you think the large growth rate as of recent is a peak, it might. It's entirely up to you. That is your assessment to make, and no one can predict the future with certainty. Make your best guess. Weigh the risk vs. the reward. Use your brain. All those good things. Obviously, I'm not trying to make that prediction for anyone. Go run some numbers and see if it makes sense, use a variety of growth changes and see how the money works out.
I'm not sure how soon I will be able to add additional shares or at what price. The absolute earliest would be Wednesday.