Since the vulnerability and importance of a benchmark varies over time, restricting the scope by reference to indices that are currently important or vulnerable would not address the risks that any benchmark poses in the future.
Toisc go n-athraíonn leochaileacht agus tábhacht tagarmhairc le himeacht ama, ní rachfaí i ngleic leis na rioscaí a bheidh ag aon tagarmharc san am atá le teacht dá ndéanfaí an raon feidhme a shrianadh trí thagairt a dhéanamh d'innéacsanna atá tábhachtach nó leochaileach faoi láthair.