I'd say cash out your initial investment, plus a little interest earned? and let the rest ride. Its all a confidence game. I bought my first .1BTC when it hit $900 the first time. I knew I was getting in at an all time high but if I didn't own any I couldn't learn what it was. Being honest with myself built my confidence because I got out of it exactly what I wanted, knowledge. I understood what it was and that it was and still is the best form of money available. Just stick to your principles and learn as much as you can.