Much bigger than non-derivative stock market for sure.
"The derivatives market is, in a word, gigantic—often estimated at over $1 quadrillion". The stock market would be puny in comparison. This is quite well known so was quite surprised by your objection.
The derivatives market is much larger than the stock market, both in sheer trading volume and total face value. While global stock markets represent a total value of roughly \(\$120\) trillion, the estimated notional value of the global derivatives market easily exceeds \(\$500\) trillion to \(\$1\) quadrillion.
Derivative markets are necessary for price discovery but when they tower over in volume over the market whose prices it was supposed to discover it is serving a purpose that towers over its justified/motivating purpose.
Also, disagree on options and futures market. They do provide important economoc function of price discovery and insurance against risk