How often is SPX value updated.

[donnap]

Beginning in 1986, the index value was updated every 15 seconds, or 1,559 times per trading day, with price updates disseminated by Reuters.

Is this still accurate?

 

[Real Money]

No. It's much faster now. (CBOE data)

 

[SunTrader]

TradeStation $SPX.X CBOE feed updates once a second, then for some reason 1261 times the last minute @ 400pm EDT

 

[donnap]

Thank you for the replies.