You can sell or hold depending on your needs. Currently, bitcoin is worth more than $ 10000 so if you want to take profit you can sell. But I think the bitcoin will continue to increase in the future, so you can keep it until the bitcoin reaches $ 15,000 by the end of 2017.
It's really up to you, OP. A lot may say, even experts, that the price of bitcoin would continue to increase in the future but if you were to think otherwise, then cashing out at this price wouldn't be so bad. If you've already profited from the moment you bought your bitcoin and feel satisfied with your profit, then my advice would be to cash out. If you're inclined towards long term investment and also believes that bitcoin will have much greater value in the future, then just continue to hold it. Base your decision on what's most suitable for you.