one year is enough for us to hold our Bitcoin. You can sell it and start another holding process by buying Bitcoin when the price is cheap. Many people have succeeded with this way and I doubt that you can fail. Only hold Bitcoin in more than 5 years when you have a good capital.
Let's say you bought 1 BTC last january 2014, you would have paid around 620. One year after, your BTC dropped to less than 200, not a good deal !
Point is that you only lose when you sell your coins at a price lower than where you bought them at. If you don't sell you don't lose anything. If you know what you do, then in your given example the best option would be to use that 200 price to start buying as many coins as possible to average down the buying price of your initial investment. Only noobs cash out their coins with such insane losses as result....
That scenario is a pointer to the fact that long term Bitcoin investment is not necessarily determined by length of time, but by the positive difference between the current price and price at the time of purchase. Evidently the technology is still evolving and the right thing to do is not to conclude all too soon what the future holds for something that is still taking shape. To that effect, following the developments in the market and the industry would serve as better guide to what decisions an investor takes.