Thirty-six stocks were added to the consumer discretionary sector of the Russell 2000 in this year's reconstitution of the small-cap index, while 50 were removed.

Shares of diet company NutriSystem Inc. dropped Monday after the company's stock was cut from the Russell 1000 index of large-capitalization stock.

Nine companies in the consumer discretionary sector are being to be added to the Russell 1000 in this year's reconstitution of the large stock index, while 13 in the sector are being removed.