20% change from one day to another is really too much for every day use, but if it is annually/yearly, then it is okay.

If it is being used for commerce. A grocery store, which typically operates on a 6% margin does not want a 20% drop in the value if HBD if it was used for that. That would mean a 14%, on average, lost on each product sold that day.

The daily change in HBD/USD is currently -0.53%, which is acceptable. The daily change is +0.36% for EUR/USD.

When it comes to commerce, that doesnt matter to most people since they are transacting in one currency. So the price of the EURO in USD does not affect most of the shoppers or account holders in the Eurozone.

As for those companies who operate on an international scale, this is basically an accounting situation since they have operations often where they are selling their products. Hence, a US company will keep EURO on hand to pay the bills for their EU operations.