McGraw-Hill's S&P Dow Jones Indices has brought in a pair of stocks to help populate two of its signature products. On May 30, the S&P MidCap 400 will now be home to Domino's Pizza (NYSE:DPZ). The stock replaces Plains Exploration & Production, which is to be acquired by Freeport-McMoRan Copper & Gold.

Meanwhile, starting May 31, the S&P SmallCap 600 will be host to Cynosure (NASDAQ:CYNO). That issue replaces NCI Building Systems. The latter has announced the conversion of some of its preferred stock, with the result that the firm's public float has fallen below the mandatory 50% required for inclusion in the index.

Fool contributor Eric Volkman has no position in any stocks mentioned. The Motley Fool owns shares of Freeport-McMoRan Copper & Gold. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.