The CBOE S&P 500^{®} Implied Correlation Indexes
The CBOE S&P 500 Implied Correlation Indexes are the first widely disseminated, marketbased estimate of the average correlation of the stocks that comprise the S&P 500 Index (SPX).
Using SPX options prices, together with the prices of options on the 50 largest stocks in the S&P 500 Index, the CBOE S&P 500 Implied Correlation Indexes offers insight into the relative cost of SPX options compared to the price of options on individual stocks that comprise the S&P 500.
 CBOE began disseminating daily values for the CBOE S&P 500 Implied Correlation Indexes in July 2009, with historical values back to 2007.
 CBOE calculates and disseminates two indexes tied to two different maturities, usually one year and two years out. The index values are published every 15 seconds throughout the trading day.
 Both are measures of the expected average correlation of price returns of S&P 500 Index components, implied through SPX option prices and prices of singlestock options on the 50 largest components of the SPX.
Ticker symbols are KCJ, ICJ and JCJ are "rotated" as time elapses. For example, as of December 2013:

KCJ
 Jan 2015 maturity S&P 500 implied correlation
 Calculated using Jan 2015 equity options and Dec 2014 SPX options
 Quotation is suspended after the Nov 2014 SPX expiration

ICJ
 Jan 2016 maturity S&P 500 implied correlation
 Calculated using Jan 2016 equity options and Dec 2015 SPX options
 Quotation is suspended after the Nov 2015 SPX expiration
 JCJ
 Not quoted until after the Nov 2014 SPX expiration
 Jan 2017 maturity S&P 500 implied correlation
See S&P 500 Implied Correlation Indexes  Historical Data
The CBOE S&P 500 Implied Correlation Indexes may be used to provide trading signals for a strategy known as volatility dispersion (or correlation) trading. For example, a long volatility dispersion trade is characterized by selling atthemoney index option straddles and purchasing atthemoney straddles in options on index components. One interpretation of this strategy is that when implied correlation is high, index option premiums are rich relative to singlestock options. Therefore, it may be profitable to sell the rich index options and buy the relatively inexpensive equity options.
"One of the perceived benefits of owning a portfolio of stocks is diversification related to the correlation between stocks. While less correlation between stocks in a portfolio typically leads to greater diversification, the correlation between stocks is constantly changing, and in times of market stress the correlation increases as stock prices tend to move together. As a result, the diversification benefits of a portfolio of stocks may be less than initially anticipated."
 Joe Levin, CBOE Vice President of Research and Product Development
About the CBOE S&P 500® Implied Correlation Indexes
The CBOE S&P 500 Implied Correlation Indexes measure changes in the relative premium between index options and singlestock options. A single stock's volatility level is driven by factors that are different from what drives the volatility of an Index (which is a basket of stocks). The implied volatility of a singlestock option simply reflects the market's expectation of the future volatility of that stock's price returns. Similarly, the implied volatility of an index option reflects the market's expectation of the future volatility of that index's price returns. However, index volatility is driven by a combination of two factors: the individual volatilities of index components and the correlation of index component price returns.
Intuitively, one would expect that the implied volatility of an index option would rise with a corresponding change in the implied volatilities of options on the index components. Yet, there are times when index option implied volatility moves and there is no corresponding shift in implied volatilities of options on those components. This outcome is due to the market's changing views on correlation. The relationship between the implied volatilities of options on an index and the implied volatilities of a weighted portfolio of options on the components of that index, therefore, becomes a measure of the market?s expectation of the future correlation of the index components  the "implied" correlation of the index.
For example, from November 20, 2008, through May 29, 2009, the closing value of ICJ ranged from a low of 56.54 on November 21, 2008, to a high of 74.78 on March 20, 2009. During the same time period, the CBOE Volatility Index (VIX) declined significantly from a recordhigh close of 80.86 on November 20, 2008 to around 40 in midMarch and 29 at the end of May. Conversely, ICJ remained relatively high with a closing value of 58.94 recorded on June 30, 2009, possibly signaling an expectation that equity prices would continue to move together.
More Information
CBOE S&P 500 Implied Correlation Index White Paper
S&P 500 Implied Correlation Historical Data
Delayed Quotes
Other CBOE Volatility Strategy Benchmarks
CBOE VIX Premium Strategy Index  VPD
CBOE Capped VIX Premium Strategy Index  VPN
CBOE S&P 500 VARBX Strategy Benchmark  VTY
CBOE S&P 500® 3Month Volatility Index®  VXV