actually i am underestimated bitcoin in 2015 when i am first time knew bitcoin. but after the end of 2015, i know the price is start to increase, i read many source and i learn many thing, then i realize that bitcoin is different than any investment i know. so i start to believe in bitcoin and finally i use bitcoin and in 2016, i see the price is increase more. finally in the middle of 2016, the price start getting up and this year, bitcoin price reach the highest price that i can see. so from time to time, i am trying to be sure and believe with bitcoin in any circumstances.

If there exist such kind who thinks of Bitcoins as some ponzi scheme, they are the illiterate ones than. I would recommend them to Google their questions and clear their doubts before opening their mouths. If someone does not care about his loss then I would let him taste it.

yes, we used to. Couple years ago, Bitcoin was really underestimated and even many people think that Bitcoin was a scam. At that time, Bitcoin was invaluable. That's why it couldn't bring enough trusts to us. However, It is different now, Bitcoin has given hopes to people.

Yes, bitcoin has been greatly underestimated in the past and many people still do not believe in it. I don't really get your analogy about the old train. Btc is not an old train, it is growing, developing and facing innovation. It is not stuck in the past.

it's my first time to know bitcoin I underestimated and it turns out my opinion about bitcoin wrong, I just believe bitcoin after my brother succeed in bitcoin, since then I also invested in bitcoin and I admit my mistake about bitcoin

Everyone including you and me underestimated it. Otherwise we would have bought a long time ago. Lots of people never thought it would go above $100. Then it went above $1,000. Then people doubted if it would go above $3,000. I personally thought it was going to crash, but sure enough it went above $3,000 and then $4,000! Now, I do not doubt Bitcoin any more. My opinion is someday it will be worth over $1,000,000.