Vertiv, Lumentum, Coherent, EchoStar set to join S&P 500

March 6 (Reuters) - S&P Dow Jones Indices said on Friday that data center equipment maker Vertiv VRT.N, photonics product makers Lumentum LITE.O and Coherent COHR.N, and telecom company EchoStar SATS.O will join its flagship S&P 500 .SPX index.

The S&P 500, widely regarded as the benchmark for U.S. large-cap stocks, is tracked by trillions of dollars in index and exchange-traded funds, making changes to its membership closely watched by investors.

Here is an overview of the change to the index and stock reaction:

• Vertiv shares jumped nearly 6% in extended trading on the news, while EchoStar rose about 4%

• Companies added to the S&P 500 often see their shares rise as index-tracking funds buy the stock to replicate the benchmark, boosting demand and liquidity.

• Lumentum and Coherent were also last up 1.7% and 0.4%, respectively, after the bell

• The new entrants will replace dating platform Match Group MTCH.O, managed care company Molina Healthcare MOH.N, food processor Lamb Weston LW.N and payroll software maker Paycom PAYC.N.

• Companies removed from the index can come under selling pressure as those same funds sell the shares to rebalance their portfolios.

• Paycom was last down 3% after the bell, while Match Group declined 0.7% and Molina slipped marginally.

• S&P Dow Jones Indices said the changes will take effect before the market opens on March 23 as part of the quarterly rebalance.