NASDAQ Biotech Index changes rebalancing procedures

NASDAQ OMX Group Inc. (NASDAQ:NDAQ) said it will change the methodology of the NASDAQ Biotechnology Index (NASDAQ:NBI) due to "considerable" growth in the biotech sector, "particularly in the last six months." Effective June 21, the index will be rebalanced each quarter so the maximum weight of any index security does not exceed 8% and no more than five securities are at that cap. Previously, the index was rebalanced if the single largest market cap index security was greater than 24% and if the collective weight of all index securities with weights greater than 4.5% was greater than 48% of the index. The exchange said the changes will ensure the index's securities are closer in line to their actual market caps. Additionally, the index will change to an annual evaluation in December from semi-annual evaluations in May and November. ...