CME said in a statement to clients that all Globex markets have been halted at around 740ET, according to an email document seen by Bloomberg.

"We are aware of this, and we are currently looking into this,” said CME spokesperson Gan Lee Meng.

S&P Futures have stopped while FX markets remain active...

And Bond futures are also not trading...

Commodities are also not trading...

The issue affects a slew of other markets, including eurodollar futures, grains, crude oil and natural gas.

Hello! Thank you for reaching out. It appears that the CME group has halted trading due to technical difficulties. This is not an issue on our end. We will be sending out a mass communication when things are back up and running. ^WG — TD Ameritrade (@TDAmeritrade) February 27, 2019

Traders, with nothing to do now, have taken to Twitter...

🧐 CME / Globex down ... 🤬🤟 pic.twitter.com/o5B240GLiJ — Miro Kahanek (@MiroKahanek) February 27, 2019

CME issues https://t.co/dxwEQfHT1M — Thirty Lake Capital (@thirtylake) February 27, 2019

Finally, as one veteran trader scoffed, now's the perfect time for India to drop a nuke on Pakistan as it only matters to the world if the S&P 500 drops.