You need to have atleast 0.1 Btc as per my understanding to start actually trading and get some small returns to it . You can trade Btc with some new altocoin and exchange back to Btc again with some gains for holding for some days .
i think we can even start trading from less that 0.1 bitcoin. i think there are so many cheap alt coin which one can buy thousand n number, but still they have the ability to increase its price too high. therefor even investing your money in alt coin will also be wise decision, and hope that one will be able to get good pofit from