It said that the last two years, bitcoins has been losing value. What would happen in the future? And what is the reason of this?
2 Answers
To be honest, no one knows. Assumptions or guesses about the future are exactly that, just assumptions. We could however look at what could make the price go up or down.
A new cryptocurrency
This might make the price of bitcoin go down, since there would be less people working with bitcoins and more people working with a new 'altcoin'. However, most people get into altcoins by buying bitcoins and then trading bitcoins for altcoins, so this is also in a way a positive thing for bitcoin.
Early adopter(s) cashing out
The people who got into Bitcoin pretty early on (people who bought 1000 BTC for $1 or less) might cash out at any time, pushing the price down. Most 'whales' cashing out 'dump' their bitcoins, instead of slowly selling bunches of 10 BTC at a time, so they do impact the worldwide price.
More people getting into bitcoin
This would make the price go up. The amount of possible available coins stays the same (21 million) and the amount of available coins slowly increases. If there is a larger increase in users than there is an increase in coins, there will be a rise in the price.
This can also reverse, if there are not enough new users (in a month / a year) the price will go down for the same reason.
The mining reward halving
This causes the bitcoins mined per block to halve, making the release of bitcoins go slower. This means the supply will slow down a bit. If the demand would stay the same and/or rise, the price would rise.
[Please edit this answer and add more possible reasons]
Really this is a good question, in fact as @Mr Jones said, no ones can say what are going to happen in the bitcoins markets. Basically you have to think how the bitcoins are create: thanks to the computer algorithms. We know that the last years bitcoin has been losing value, as you can check in the charts,(this page is very usefull http://bitcoincharts.com/markets/) You should have some knowdelge about technical chart analysis (you can learn more about this). Let`s do it to the bitcoin chart: You can see that the bitcoin is loseing value.