What is a SIF? — Specialised Investment Fund (Luxembourg)
A SIF is a Luxembourg fund under the Law of 13 February 2007, reserved for well-informed investors and authorised and supervised by the CSSF at product level. It can invest in any asset class under a flexible risk-spreading discipline, which is what made it the workhorse of Luxembourg alternative funds before the RAIF arrived. Unlike a RAIF, a SIF is approved by the regulator before launch.
The two numbers that matter were both reset by the toolbox-modernisation Law of 21 July 2023: a non-professional "well-informed" investor now needs a minimum commitment of €100,000 (down from €125,000, unless certified as expert), and the fund's net assets must reach €1,250,000 within 24 months of authorisation (extended from 12). Institutional and professional investors qualify automatically.
The operating framework moved in December 2025: CSSF Circular 25/901 repealed the old 30%-per-issuer guideline (Circular 07/309) and put SIFs on the consolidated framework — in practice a 50% per-position limit, since SIF investors are well-informed by law. Existing funds are grandfathered; every new fund or compartment lands on the new rules.
The practical gotcha: the SIF's remaining pitch versus the RAIF is optionality on the manager — a SIF can sit under a sub-threshold (registered) AIFM; a RAIF cannot. If you want CSSF product supervision as a selling point, or you're below the AIFMD thresholds, the 2007 vehicle still earns its file.
Where this appears on FundRegTracker
- CSSF Circular 25/901, consolidated — the SIF's current investment-limit framework
- NAV error correction across domiciles — SIFs self-set their NAV-error threshold, capped at 5%
- Where to domicile a private fund