I see that CBOE has halted trading all SPX options, which means the VIX cannot be calculated. Yet VIX futures are still trading and we are very close to the last trade date for the March contract.
I suppose traders can still price options (even though they can't trade them) and thus back out a volatility. But what if the trading halt lasts until the valuation date (18th March). How will anyone work out the final valuation?