$4 per bitcoin? Not even the EUR and GBP have ever reached that in my recollection.
Keep in mind that the exchange rate is a function of several inputs, one of which is the rather arbitrary fact of how much total currency is in circulation. There are many fewer BTC than USD, EUR, GBP, etc. (about one million times fewer, to be precise). And conversely, there are many more JPY in circulation, which is part of the reason the yen is much cheaper than the US dollar.
That doesn't mean there's not a BTC bubble. There may very well be. But you can't do the comparison you just did and expect it to be meaningful. If the BTC protocol had specified the decimal point one place to the left, BTC would be trading at 0.40 USD right now, not 4.00 USD. There'd just be 10 times as many.
What you have to do is ask how much total wealth the world will want to store in BTC, and then divide that by how many BTC there are. The answer to the first question is a huge unknown. The answer to the latter is specified by the protocol: 21 million.
Given the current valuation though of $3.5 and the fact that there are approximately 6M bitcoin in circulation, that gives quite a large valuation on what seems to be a very limited market at the moment. You are right though, my initial simple comparison of numbers leads only to inaccuracies
You seem to be knowledgeable in this field. I have no idea about it and would like to get a small insight. Can you recommend a tutorial (Preferably less than 40 pages) that explains some of the main concepts?
Keep in mind that the exchange rate is a function of several inputs, one of which is the rather arbitrary fact of how much total currency is in circulation. There are many fewer BTC than USD, EUR, GBP, etc. (about one million times fewer, to be precise). And conversely, there are many more JPY in circulation, which is part of the reason the yen is much cheaper than the US dollar.
That doesn't mean there's not a BTC bubble. There may very well be. But you can't do the comparison you just did and expect it to be meaningful. If the BTC protocol had specified the decimal point one place to the left, BTC would be trading at 0.40 USD right now, not 4.00 USD. There'd just be 10 times as many.
What you have to do is ask how much total wealth the world will want to store in BTC, and then divide that by how many BTC there are. The answer to the first question is a huge unknown. The answer to the latter is specified by the protocol: 21 million.