Taking a long position with bitcoin is not such a good idea anymore. All indicators show that the chances of it doubling in price are very slim. You can make much more by arbitraging coins..

Bought 1BTC on Bitfinex for $10,454

Sold 1 BTC on cex  $11391

Net profit: $937  - 0.5 -1 % fees

Total time: 20 minutes

http://www.arbitrage.expert/