Dear Client, Interactive Brokers is pleased to announce the reduction of European stock commission rates for the tiered commission model. On April 1, 2019, the most expensive tiers above 0.05% will be eliminated for all currencies: In EUR, CHF, USD, PLN, ILS and HUF-denominated products, commissions for all Monthly Trade Values up to EUR 50,000,000 will now have a fee per trade value of 0.05% (5 bps). In the United Kingdom, all Monthly Trade Values up to GBP 40,000,000 will now have a fee per trade value of 0.05% (5 bps). All exchange, clearing and regulatory fees will continue to be passed through. Please note there is no change to the order minimums or maximums, flat rate commissions and commissions for Norway or Sweden (where commissions already start at 0.050%).
This change only applies if you're on the "tiered commission model". Nothing changes if you're on the "flat rate commission model".
I forgot the details, but my understanding is that the flat rate is cheaper if you are trading only small sizes.