Where can I find the details of TBanque’s spreads?

Spreads are defined on a per asset basis. It is not possible to provide exact spreads for assets which use a variable spread (such as cryptoassets) because the market spread is not determined by TBanque and its variability cannot be controlled.  

As such, when defining spreads for such assets, TBanque will always quote the spread on the basis of “market spread + fee” (and will quantify the fee accordingly).  Conversely, TBanque is able to quantify the exact spread in the case where assets are provided on a fixed spread basis (this does not apply to cryptoassets, which use variable spreads, as mentioned above).  As such, the full spread is quoted accordingly.