AMZN added to SP500

[Sniper]

Shares of Amazon.com rose in after-hours trading Monday following an announcement that the stock would join the S&P 500 index.

Amazon will replace AT&T, which is soon to be acquired by SBC Communications.

Shares of Amazon recently rose 6.6% to $45.32 on Instinet.

Stocks joining major indices will often see a rise following such announcements as index-based funds look to swap into shares of the latest inductee.