The Earth barely missed a massive solar storm aka a coronal mass ejection a couple of years ago that had it happened just a few days off, would've fried out power grids and sent us back to 18th century living.
[
science.nasa.gov...]
"I have come away from our recent studies more convinced than ever that Earth and its inhabitants were incredibly fortunate that the 2012 eruption happened when it did," says Baker. "If the eruption had occurred only one week earlier, Earth would have been in the line of fire.
We'd still be fixing things about now.
Most likely global starvation and war would've erupted, lots of warlords, it would be real-life Mad Max except cars wouldn't run. Forget the elderly, the impaired, or people needing medical attention and medication, they would quickly perish. It would've been a huge culling of the population for sure.
The first thing that came to my mind was how would you prove to the bank that they had your money?
How would you get any cash?
Even if you had it, would it have any value?
I'm guessing people would be trading food, water and fuel and cash would be trash so STOCK UP!