Problem
Suppose you, a speculator in currencies, observe the following professional quote from Citibank. (Note: This is a professional quote: the base currency is listed first and the quote currency second) GBP/USD 1.3000 - 1.3010 Suppose you sell USD 100,000,000 and receive GBP. Then, 5 minutes later, you sell all the GBP you just received in exchange for USD. How many USD would you lose due to Citibank's bid-ask spread (tr transaction costs)?