Increasing equity values helped drive options trading in April, as market participants bought contracts that would pay off in the event of a market decline.

A shade more than 371 million options contracts changed hands last month, up 16% from year-earlier levels, according to the Options Industry Council. Year to date, options volume is down about 1%.

The benchmark Standard & Poor’s 500 Index touched new record highs in late April, pushing up interest in derivative products such as the CBOE Volatility Index, which established single-day volume records for both options and futures.

“April VIX options open interest at expiration was the highest it’s ever been, tied to the fact people were hedging their long market exposure,” PTR Inc. equity index options broker Mark Caffray told Markets Media. “They were buying hundreds of thousands of out-of-the-money call spreads.”

April’s volume increase was strong but at least one CBOE floor trader tempered bullishness, noting that the comparison month of April 2012 was especially weak .

Beginning on April 4, 2013, the S&P 500 was at about 1,530, then rose nearly four percent to an all-time record of 1,590 on April 11, and by the 18th of the month, was back at 1,530. The closely followed index closed the month near 1,600.