A flurry of crypto options activity ahead of Bitcoin's halving contributed to derivative volumes hitting a new all-time high in May.

In a new report Thursday, London-based data aggregator CryptoCompare found crypto derivative volumes increased 32% to $602 billion. That's a new all-time high, squeaking past the previous record of $600 billion set in March.

Most of the heavy-lifting came from Huobi, OKEx and Binance. The three exchanges made up 80% of May's derivative activity. Huobi was the largest, with $176 billion in volume, up 29% from April. OKEx and Binance came in with $156 billion and $139 billion, respectively.

But CryptoCompare also found there was a notable increase in trading activity around crypto options, contracts giving the owner the right to buy or sell the underlying at a specified date and price.

Volume on options exchange Deribit more than doubled to $3.06 billion in May. On the 10th of that month, the day before the Bitcoin halving event, $196 million worth of trades passed through Deribit, making it the single-biggest day in the platform's four-year history.

Similarly, institutional exchange CME, which only released its own crypto options earlier this year, reported a 16-fold increase in monthly activity compared to April. Like Deribit, there was a significant uptick in trading activity in and around the Bitcoin halving event.

Speaking to CoinDesk, CryptoCompare founder and CEO Charles Hayter said the surge in crypto options trading suggested a "more sophisticated, diverse class of investor" is getting involved during a period when not only was there a halving event, but also "unprecedented financial measures" taking place around the world following the coronavirus outbreak.

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CryptoCompare also found that crypto derivatives gained market share in May. While spot volumes continue to make up the lion's share, representing roughly 68% of total trading activity, crypto derivatives saw their share increase to 32% in May from 27% in April.