Do small AIFMs need to file STORs under MAR?
Last reviewed 23 June 2026.
Yes. The Market Abuse Regulation's STOR obligation applies to any person professionally arranging or executing transactions, regardless of firm size. There is no exemption for a small AIFM, a one-person compliance function, or a fund without a dedicated surveillance desk.
What changes with size is resourcing, not the obligation
MAR doesn't scale the obligation down for smaller firms -- it expects smaller firms to scale their arrangements to their size and complexity instead. In practice that means: a large bank might run a dedicated surveillance team across multiple desks; a small AIFM needs the same detection capability, just delivered by fewer people (often one MLRO or compliance officer) supported by automation rather than headcount.
What a small AIFM actually needs in place
- A way to screen every day's trades for the common abuse patterns -- informed trading, off-market execution, unusual volume -- without relying on someone remembering to look
- A documented process for what happens when a pattern fires: who reviews it, on what timeline, and how the STOR decision gets recorded
- An audit trail showing the surveillance ran, even on days nothing was flagged -- regulators ask "were you looking," not just "did you find something"
The practical pattern
Automate the detection (it's a pattern-matching problem, not a judgment problem), and reserve the human's time for the small number of genuine alerts that need a STOR decision. That's the difference between "we can't afford a compliance team" and "we don't need one sized like a bank's."