If I were you and willing to do some trading on Bitcoin's price, I'd better head to some automated platform that allows me to open and close an order in a few seconds.
Well the question is how much you are going to start trading with those automated platforms. I think 0.01
BTC i already enough to start minimum trading. And that is going to depend on how you are going to make your capital grow with the potential alt coins that you are going to buy, just make sure you know how to trade.
That's enough and that is already a decent amount of money to start for you journey in trading, and that is just advisable for every trader who are starting up because when you are new you cannot guarantee to make profit all the time, you are bound to lose at first but with small amount you can bear the loses.
With 0.01 bitcoin, you can buy 0.5 Ethereum and 5 ETC. That is good amount to play with initially.