How to load all information Currency properties by currency code?
As a currency is just an entity you can do the following:

$currency_code = 'AUD';
$entity_type_manager = \Drupal::service('entity_type.manager');
$currency = $entity_type_manager-&gt;getStorage('currency')-&gt;load($currency_code);
ksm($currency); //check out what's available

//eg get sign
$sign = $currency-&gt;get('sign');


Good Luck