Lululemon’s stock to join S&P 500 index

Lululemon Athletica Inc.’s stock rallied more than 5% in the after-hours session Friday after S&P Dow Jones Indices said the stock will join the S&P 500 index next week.

Lululemon’s
LULU,
+1.00%
shares will replace video-game company Activision Blizzard Inc.’s on the S&P 500
SPX,
the index provider said. The changes are effective before the stock-market open on Wednesday.