What was the value of gold 10 years ago? was the price that people would pay for it. It wasn't the cost, it was the actual value. Same as BTC 2 years ago, same as oil 1000 years ago, it had no value because nobody was willing to pay anything for it. Maybe in the future we discover that we can make gold from iron and it's value plumets. It's it actual value that plumets, not the cost.
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Something can have value for me but not for you. For example I may be willing to pay $1000 for something without any value for you, like my dog, if I loose him. What is the cost of the dog? The value is the real indicator of value, not the cost.
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This statement shows that you do not work in the finance industry, and do not have any formal education on the subject.
Your dog comment is actually in contrast to the rest of your statements and shows that maybe you do understand the difference between cost and value. For example, the cost of your dog may be $500. You may value the dog significantly higher than that, so buying that same dog would be considered the best investment of your life, even though when you sell that dog, all you're seeing is losses from expenses and you did not see any return on your investment. While this isn't a perfect example due to your assigning value on the dog, using some imagination and swapping the dog value with USD value, and the cost with the BTC cost of investment, you prove my argument quite well.
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Well, not everything in this life it's an investent. I don't consider an invetment by giving someone a reward for bringing me my lost dog. Not everything that has a value is an investment. A piece of gold that was extracted 300 years ago can change it's value but not it's cost. The real price of something it is given by it's value not by it's cost. A btc has the same value regardless of it beying mined 4 years ago with a laptop that cost $500 and consumed 80 W/h as the one that was mined 5 months ago with a Teraminer that cost (at that time) 15k usd and consumed 2.2 kW/h. The same Teraminer cost is constant but it's value changed. So the price is given by the value not by the cost, same as securities.