Trading 10,000 BTC at a time is bad for many reasons.
Trading 1,000 BTC is better.
Trading 100 BTC is better yet.
..etc
If you have a bot, there is no reason to do large trades when you can do many smaller trades (all thing being equal).
I make small trades because I'm still not confident I'm any good yet, not that small though.
This is another reason. You can put $1 in and pretend it is 100% of the money you have.