You base the surcharge on what the swap costs. The cost of the swap takes into account the market's idea of what the ruble is going to do vs. the dollar. Basi

You base the surcharge on what the swap costs. The cost of the swap takes into account the market's idea of what the ruble is going to do vs. the dollar. Basically, you make the customer buy insurance against the ruble losing value against the dollar. It's like charging a subprime borrower PMI.