Not a Ponzi scheme. More like Tulip mania. Ponzi is one person selling someone an investment and giving them interest payments from later investors and pocketing the money without actually investing in anything. That's not going on here although some investment firms are selling it as a good investment, but they're not pocketing the investors money, it's just basically gone when the value goes down. So doesn't meet any of the requirement for a Ponzi scheme. Tulip mania was where the price of Tulips skyrocketed and then came crashing down when everyone grew them to cash in on it. In this sense Bitcoin is limited in the number of bitcoins that can exist so supply can't increase. But there are many other crypto coins out there and the value is only worth whatever someone is willing to pay. When/if people come to their senses it can come crashing down. I knew about Bitcoin when it was $600 and thought it was overvalued then. Guess it means I'm not a good investor/gambler. I still hear talks of how some think it could still go to $1 million eventually.Agree. I think some money was put in the system to get it kick started. Since them additional coins have been mined, and the other coins purchased gave the money to the sellers. I kind of doubt that the actual money behind BTC is a lot less than the product of $18,000 times the number of existing coins. If I am correct, it is definitely a Ponzi scheme. If I am wrong, I would certainly look for someone to explain how it is not and that the system is backed by actual funds remotely equivalent to the market capitalization of the system.
Social security are controlled by certain rules from the government. Currently those rules means it will be insolvent at a certain point. But Congress can just as easily change the rules except that no one wants to touch it as it's considered the 3rd rail. What will happen is that as we get closer to the insolvency date, it will be tweaked but nothing will happen before then.Like social security or the stock market.
Stock market is not a zero sum game, in theory stocks can continue to go up as business continue to grow. But you can't buy one stock and hold it forever, there are always new companies out there growing and old companies dying and the trick is to figure out which one is which. Of course if the overall economy goes down, the stock market in general will go down but even in a down market there are still stock market winners, just fewer of them.