The US Federal Reserve is obsessed with market reactions to its policies. Because of this, anytime the Fed plans to announce a major change in policy, it preps the markets via numerous leaks and hints… oftentimes for months in advance.
One weekend. The process was not gradual. It was sudden and it was total: once it began in earnest, the banks were closed and you couldn’t get your money out (more on this in a moment).
If you think this sounds like some kind of conspiracy theory, consider that France just banned any transaction over €1,000 Euros from using physical cash. Spain has already banned transactions over €2,500. Uruguay has banned transactions over $5,000. And on and on.