If you are syncing HubSpot with Salesforce and run a multi-currency Salesforce organization, you may see this alert in Hubspot, "It looks like you're using a Salesforce multi-currency organization. This is unsupported, and may cause some revenue fields to sync incorrectly. Would you still like to enable opportunity sync?"
At this time, since we aren’t able to do the exchange, you will see the number value from Salesforce with whatever currency symbol you selected in HubSpot. For example, if you have 100 EU in Salesforce and you’re using USD in HubSpot, it will show as $100 in HubSpot.