I don't think the vast majority have any clue just how big the derivatives market has become. Frightening doesn't even begin to cover it, terrifying is far nearer the mark.
The derivatives market is, in a word, gigantic—often estimated at over $1 quadrillion on the high end. How can that be? Largely because there are numerous derivatives in existence, available on virtually every possible type of investment asset, including equities, commodities, bonds, and currency. Some market analysts even place the size of the market at more than 10 times that of the total world gross domestic product (GDP). However, other researchers challenge these estimates, arguing the size of the derivatives market is vastly overstated.
KEY TAKEAWAYS
The derivatives market is said to be over $1 quadrillion dollars on the high end, but some analysts say the market is grossly overestimated. The higher end of the estimates includes the notional value of derivative contracts.
There is a large difference in the notional value and actual value of derivatives—$640 trillion versus $12 trillion—as of the first half of 2019.
The Range of Estimates
Determining the actual size of the derivatives market depends on what a person considers part of the market, and therefore, what figures go into the calculation. The larger estimates come from adding up the notional value of all available derivatives contracts. But some analysts argue that such a calculation doesn't reflect reality—that the notional value of a derivative contract's underlying assets, the financial instruments the derivative is pegged to, does not accurately represent the actual market value of derivative contracts based on those assets.
https://www.investopedia.com/ask/answers/052715/how-big-derivatives-market.asp