To successful start buying low and selling high, you have to go through some trading platforms where you can see the pairs you wishes to trade and that can be through an exchange like Binance or a forex broker that trade cryptocurrency. So what you have said is not clear enough to me.
I guess OP has confused to ask about what he wants to know.
How do you trade? Buying low and selling high, that is the key.
Perhaps, he means about Mycelium wallet since I read on the other thread that saying with Mycelium, we can buy and sell bitcoin with any sellers available on the Mycelium market.
And related to the leveraged trade, I didn't make that trade for a long time ago, and now, I am trying with using usual trading in the binance, bittrex, poloniex and others.