I invested about $3500 in bitcoin on 19th December, 2017. After that Bitcoin price has been decreasing and this decreasing is ruing non stop. Now I am in loss amount of $700. I am so much frustration with my investment

. I am waiting for better time. If you have any idea please share in this thread.

If you haven't sold any of the Bitcoin you bought then you haven't lost any amount yet. It just happened that you bought Bitcoin when it is at it's peak so experiencing down time is normal. Just keep on holding your Bitcoin since BTC is very much profitable in the long run. Patience should be your option for now. Bitcoin is Bitcoin, only weak hands suffer
