Yeah I guess currency exchanges / futures have always been 24/7 as there is always an open market somewhere in the world. Crypto currencies are close to that I guess.

I wonder if equity markets will one day move to always on, I hope they do.

With more investment options such as crypto currencies, I wonder if they will eventually do it to stay competitive to investment cash.

Nothing worse than pre-market and after hours shenanigans in equity markets, can't pull that in an always on market.

Not for retail trading and holidays can affect pairs.

Retail trading in Forex markets is miniscule. <4% in 2013.

Source: https://www.bis.org/publ/qtrpdf/r_qt1312z.htm