With equity options, many market makers hedge by buying or selling the underlying asset in correspondence with the option's delta.
For example, if the market maker wrote 1 call option with a delta of .7 then they buy 70 shares.
How would one delta hedge with VIX options, where there are no underlying shares on the index.
Available options could include a cross-asset weighted portfolio with VIX ETF shares/nav units. Some kind of concoction with different VIX futures at differing margin levels. Or further recreating a leveraged fraction of the VIX term structure with S&P options.
Any insight appreciated