Round numbers (7500, 8000, 10000...) are always a barrier beause I think some traders decide they'll sell at this value, and naturally you define an order with a round number instead of a random value. If I was trading often, I would buy at, for example, 8000, and put an order to sell at 9000.
Wow, I have never thought of it this way. It sounds simplistic, but makes perfect sense. A perfectly plausible explanation in my opinion.