Systematic Internaliser
Brokers & RegulationA firm that fills client orders from its own book, away from a venue, under venue-like quoting, transparency and record-keeping duties.
A systematic internaliser is an investment firm that deals on its own account, on an organised and frequent basis, executing client orders outside a trading venue. The category exists in European conduct rules to bring that off-venue dealing under obligations resembling a venue's: quoting duties in some instruments, transparency requirements and record keeping, with the firm itself standing as the counterparty rather than a market.
For a retail client the practical reading is about who takes the other side. When a firm executes as a systematic internaliser it is not passing your order to a market; it is filling it from its own book and carrying the resulting position until it decides otherwise. That is a disclosed model with its own rulebook, not a hidden one, but it makes the firm's balance sheet and its own risk decisions part of your execution. The status appears in the execution policy and in the firm's entry on the regulator's register.