In general, all securities are traded per unit. Bonds are the exception, as they are traded in percentage
of the nominal value. SIX only adds accrued interest when calculating the amount to be settled. Details
of this can be found in the Rule Book[pdf].
Categorisation of securities
Order prices and quotes may only move up and down in increments called minimum ticks,
which can be found in Directive 3: Trading[pdf].
Each securities issue is assigned to a specific category in this regard.