Which currency does my store report in?

Your shop's own currency, taken from Shopify at connect and shown as read-only in Settings. Every figure in the product is in that currency, formatted the European way, and there is no cross-currency consolidation: one store, one currency, no exchange rates applied to your P&L.

If you sell in several currencies through Shopify Markets, the amounts arrive converted into your shop currency as Shopify recorded them, which keeps the statement consistent with your own payouts rather than with a rate we chose.