You can select only one currency for your marketplace to be denominated in.
We would strongly suggest you set the currency of your linked bank account to be the default marketplace currency. That is to avoid incurring currency conversion rates by Stripe and/or PayPal when you receive money in a foreign currency.
Example: If your bank’s default currency is SGD, your marketplace default currency should be set to SGD so you can receive payments without incurring currency conversion fees.
Currency conversion fees for Arcadier’s default payment processors:
PayPal: https://www.paypal.com/sg/webapps/mpp/paypal-fees
Stripe: https://support.stripe.com/questions/how-does-stripe-handle-currency-conversion