I keep reinvesting with Gemini Is this a stupid Strategy?

As you know,

On the share market you can buy a stock for lets say $1 dollar at 1000 units

Then you can buy it at 0.50 at 1000 units again.

In other words, you have two open positions that you can close when the stock goes above $1 (let's say).

When I am doing my Bitcoin I am using Gemini, and I am basically input $700 each week recurring. But it just adds the money to the one position? Why is that? Is there a better way? Is this just how it works?