Actually, no. Stock trading is settled over a period of two days only because of how the system is currently organized; it is technically possible to settle tr

Actually, no. Stock trading is settled over a period of two days only because of how the system is currently organized; it is technically possible to settle trades at the end of the day, or even in real time, and there are exchanges in the world that settle trades rapidly. The reason the US exchanges have not changed is inertia, and settlement periods have actually decreased just in my lifetime. One real reason why digital currencies are not widely deployed is crime. Already there is a growing problem of ransomware demanding Bitcoin payments; a "true" digital currency that was as convenient as Bitcoin and allowed offline (peer-to-peer) payments (which Bitcoin does not and cannot support) would enable "perfect crimes." This was a concern raised in the 90s when digital cash was being proposed: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.465.9796&rep=rep1&type=pdf https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.46... This was one of the concerns that prevented banks from adopting e-cash (as the term is understood by cryptographers), though I have been told by people who worked on this that law enforcement agencies were satisfied that they could still "follow the money" since the anonymity property was narrowly defined (banks could not link deposits to withdrawals, but banks would still know who had made a particular deposit, merchants would still be able to identify customers, etc.).