“The market (spot fx) works in three tiers: interdealer, interbank, and bank-to-client, with decreasing trade sizes and increasing spreads, respectively.”
However - in the Kaplan Qbank:
“The interbank market has the largest trade sizes with the smallest spreads. The bank-to-client market has the smallest trades sizes with the largest spreads.”
Is Interbank or Interdealer the larger of the two markets in terms of what market handles the most size, and who has the lowest spread?