Cboe S&P 500 PutWrite Index (PUT) www.cboe.com/PUT

NEW! - Cboe S&P 500 PutWrite Index (PUT) Fact Sheet (with data from June 1986 through July 2017) - 2-page PDF
NEW! - Bondarenko, Oleg. An Analysis of Index Option Writing with Monthly and Weekly Rollover. (2016)

In June 2007 the Cboe Options Exchange (Cboe) announced that it is beginning to publish daily data on the value of the Cboe S&P 500 PutWrite Index (ticker symbol PUT). PUT is an award-winning benchmark index that measures the performance of a hypothetical portfolio that sells S&P 500 Index (SPX) put options against collateralized cash reserves held in a money market account. The daily historical data for the PUT Index now extends back to June 30, 1986.

The PUT strategy is designed to sell a sequence of one-month, at-the-money, S&P 500 Index puts and invest cash at one- and three-month Treasury Bill rates. The number of puts sold varies from month to month, but is limited so that the amount held in Treasury Bills can finance the maximum possible loss from final settlement of the SPX puts.

Study on Index Options Writing by Asset Consulting Group

In February 2012 the Asset Consulting Group published a six-page paper -- "An Analysis of Index Option Writing for Liquid Enhanced Risk-Adjusted Returns". Key findings of the paper include:

  • Total Growth. Total growth for indexes since mid-1986 was 1153% for PUT Index, 830% for BXM Index, 807% for S&P 500® Index, and 368% for CLL Index (Exhibits 2 and 6).
  • Lower Volatility. The PUT, BXM, and CLL indices all had volatility that was about 30 percent lower than the volatility of the S&P 500 Index (Exhibit 4).
  • Left-tail Risk. Over the past 25 years, the worst monthly loss for the S&P 500 Index was a decline of 21.5 percent, compared to a relatively modest 8.6-percent monthly decline for the CLL Index (Exhibit 8e).
  • Risk-adjusted Returns. One measure of risk-adjusted returns, the Sortino Ratio, was 0.90 for the PUT Index, 0.75 for BXY, 0.71 for BXM, 0.50 for S&P 500, and 0.31 for CLL Index (Exhibits 10 and 11). Please note that all the indexes had negative skewness.
  • Monthly Premium Income. The average for the gross monthly premiums collected by the BXM Index was 1.8 percent. The index options usually were richly priced (Exhibits 12 and 13).

For more information, please see the six-page paper and press release.

Updated Price Charts


The BXM, BXD, BXN, BXY, CLL and PUT indices (the "Indexes") are designed to represent proposed hypothetical options strategies. The actual performance of investment vehicles such as mutual funds or managed accounts can have significant differences from the performance of the Indexes. Investors attempting to replicate the Indexes should discuss with their advisors possible timing and liquidity issues. Like many passive benchmarks, the Indexes do not take into account significant factors such as transaction costs and taxes. Transaction costs and taxes for strategies such as the Indexes could be significantly higher than transaction costs for a passive strategy of buying-and-holding stocks. Investors should consult their tax advisor as to how taxes affect the outcome of contemplated options transactions. Past performance does not guarantee future results. This web page contains index performance data based on back-testing, i.e., calculations of how the index might have performed prior to launch. Backtested performance information is purely hypothetical and is provided in this web page solely for informational purposes. Back-tested performance does not represent actual performance and should not be interpreted as an indication of actual performance. It is not possible to invest directly in an index. Cboe calculates and disseminates the Indexes. Supporting documentation for any claims, comparisons, statistics or other technical data is available from Cboe upon request. The methodologies of the Indexes are the property of Cboe Options Exchange (Cboe).