* Value of stock in March A$264 bln vs A$126 bln a year ago
* Index options trade surges
* March worst month for Aussie benchmark since 1987 (Adds New Zealand statistics in final paragraph)
SINGAPORE, April 6 (Reuters) - The volume and value of trades on the Australian Securities Exchange doubled during last month's wild market swings, the exchange operator said on Monday.
Australia's stock market posted its worst month since 1987 in March, plunging 21.5% amid a worldwide equities rout as the coronavirus pandemic worsened.
The volume of trades more than doubled to 67.5 million compared with March 2019, and the average daily trade rose 96% to 3 million, according to monthly statistics released by exchange operator ASX Ltd ASX.AX .
The total value of cash market trades rose 110% to A$264.2 billion ($159.3 billion) compared with A$125.5 billion a year earlier. There was also a 51% surge in index options, as fund managers used them to offset big swings in their portfolios.
"The market volatility was sky high," said Mathan Somasundaram, strategist at brokerage Blue Ocean Equities in Sydney. "Thematics were changing on a weekly basis."
"It's too hard to move big portfolios, but easier to do that with index options. The big volumes in index options forced the option providers to then have to trade big on equities to counter the risk. Hence we had elevated equities volume driven by elevated index options," he said.
The benchmark index .AXJO posted both its second-largest daily drop and its biggest daily rise in the month, and on the All-Ordinaries index .AORD , average daily movement was 4.1% compared with 0.3% in March 2019.
In New Zealand, figures released last week by the exchange operator NZX Ltd NZX.NZ showed a near quadrupling in the number of trades made in March compared to a year earlier, and a 68% rise in the value of cash trades to NZ$6.5 billion ($3.9 billion).
($1 = 1.6584 Australian dollars) ($1 = 1.6920 New Zealand dollars)