Bitcoin approved and discovered in the world on 2009 and the first price is $0.
And this the history and bitcoin table when discovered in the world from 2009.[Using USD Rate 2017]
2009 [Discovered] - 1btc = $0
2010 - 1btc = $0.1 - $0.08
2011 - 1btc = $0.75
2012 - 1btc = $9.04
2013 - 1btc = $301.20
2014 - 1btc = $753.01
2015 - 1btc = $451.81
2016 - 1btc = $828.31
2017 - 1btc = $3664.25 2017 - 1btc = $5838.48
From this list we know bitcoin is not stable , frequently make increase and reduction on price.
Is there a possibility of a decline in the price of the bitcoin future , in doing so we must make a choice better invest a bitcoin or not ?
I've corrected your speculation. The recent boom in pricing is due to the fact that even China banned ICOs more people still want to invest on it. If you look at the prices from year to year you can easily notice an increasing trend. Therefore, bitcoin's price is directly proportional to time. We can see some dips and crash along the way but the pricing will always be corrected in a matter of days or weeks.