1)Buy an apple for 1 dollar.
2)Then sell it for 2 dollars and buy 2 apples.
3)Repeat with 4, 8, 16, 32 apples and so on, until you managed to sell 3500 apples for 7000 usd.
4)Buy a bitcoin
Good suggestion but the main thing here is that we wont really know or hardly managed on such kind of target knowing that choosing altcoin is really pain in the ass because we wont even know if it would rise or not. Shorting $1 amount is not really sufficient and you can just buy coins worth of cents but you can actually make up some tradings but the waiting game would really be longer knowing that $1 is not really a big amount which we can freely move with our oders.2)Then sell it for 2 dollars and buy 2 apples.
3)Repeat with 4, 8, 16, 32 apples and so on, until you managed to sell 3500 apples for 7000 usd.
4)Buy a bitcoin