English to German Bus/Financial Investment / Securities Festverzinsliche Anleihen

Es handelt sich um den Monatsbericht eines Investmentfonds:
Generally, the portfolio’s emphasis on higher-quality credits was a detractor during the period; we held x.x% (at period end) in *non-index investment grade holdings*, which underperformed high yield.
Mir ist das "non-index" in diesem Zusammenhang noch nicht untergekommen.

Weiterer Kontext:
For the month ending April 30, 2009, the portfolio underperformed its benchmark, the xyz. Our underweights in CCC-rated and lower credits, which performed the best within the index, was a detractor from relative performance. Generally, the portfolio’s emphasis on higher-quality credits was a detractor during the period; we held x.x% (at period end) in non-index investment grade holdings, which underperformed high yield.