DZAIRINDEX is the value-weighted index of the SGBV's main equity compartment. It started at 1 000 on 3 January 2008 — its base date — and is recomputed at every fixing. Reading the index level on its own says nothing; reading the % change vs the base, or vs the start of the year, is what tells the story of the market.
With ten or so listed equities, DZAIRINDEX is more concentrated than a typical national index. A single mover in BIO or CPA can move the whole index 1-2% in a session. That's not a bug — it's a property of a thin market, and reading the index without checking the contributors per session can mislead.