@anon33247966, thank you very much for your research and explanation. This will help the community to understand Revolut’s FX rates.
According to the site you indicated, the spread for EUR/KES at the moment is 114.91-118.91 (=3.5%). This explains a lot. So, for some exotic currencies, you could describe your rates in two ways:
a) We charge 0.0% markup (based on whatever crappy interbank bid rate you can find on www.investing.com). That’s exactly how legacy banks did it for years.
b) We charge 1.7% markup (based on the well known mid-market rate). This option looks less attractive of course, but could prevent surprise and disappointment with future users.
This might be true for some currencies, but definitely not for all. As I wrote time and again, TransferWise offers KES with a constant 0.7% fee on the mid-market rate. So they must get a significantly better bid rate than you.
Anyway, I will now stop boring you with my “grievances” and continue using Revolut for those of my banking needs, where it really is superior.