这是业内人士说的，比较靠谱，我当然说的是Nominal Value，OTC很难清楚，所以巴菲特说是大规模杀伤性武器。

Since swaps are highly customized and not easily standardized, the swap market is considered an over-the-counter (OTC) market, meaning that swap contracts cannot typically be easily traded on an exchange. But that does not necessarily mean swaps are illiquid instruments. The swap market is one of the largest and most liquid global marketplaces, with many willing participants eager to take either side of a contract. According to the Bank for International Settlements, the notional amount outstanding in over-the-counter interest rate swaps was more than $341 trillion in 2019.1