Through the month of September, 2011 continues to see substantial equity options trading volume growth.

Investors continue to turn to options as market volatility remains high.

The Options Industry Council announced that total options trading volume for September was 391.2 million contracts, 29.5 percent higher than the 302.1 million seen a year earlier. Average daily volume stood at 18.6 million contracts, from 14.4 in 2010, also up 29.5 percent.

The Chicago Board Options Exchange is one of the first of the major options exchange operators to post September trading statistics. For the month of September, CBOE Holding’s aggregate contracts traded totaled 104.2 million contracts. Average daily volume reached 5 million contracts, up 31 percent from the 3.8 million seen in 2010.

Its main CBOE platform averaged 4.7 million contracts daily, up 25 percent. The most gains were seen in the trading of exchange-traded fund options (79 percent increase) and index options (up 42 percent).

The volumes seen in September, although a drop off from the all-time highs from August (down 28 percent), were still substantial in terms of yearly growth. Last month, it had 6.6 million contracts traded daily on average, up 88 percent from the prior year period, and a record high. Its CBOE Options, CBOE Futures and C2 exchanges each established new individual monthly volume records as well. Its index and exchange traded funds options, as well as its Market Volatility, or VIX products also reached all-time monthly trading volume highs.

CBOE’s market share fell just under 1 percentage point to 25.4 percent, including dividend trades. Its market share for index options continues to have a stranglehold, with 95.7 percent share. Its ETF options and equity options also hold 19.1 percent and 19.5 percent market share, respectively.

CBOE’s Futures Exchange trading also saw substantial gains, up 154 percent year-over-year. Its VIX futures volume was up 154 percent to 46,784 contracts ADV, or 982,462 total for the month. Total futures volume for the third quarter was just under 4 million contracts.