But I guess there is still a remaining bug. If I sum all transaction from 20th November, the sum is only 2.5 billion USDT. But coinmarketcap says it was 72 billion USDT. So maybe I missed another function call?
If I'm not mistaken, your tools are only gathering data from the on-chain transactions. On other hand, there are some movements within the exchange that not present in the data, which it makes the number is vastly different. And CMC does calculate their volume based on the reported exchanges data.
See reference below:
Volume (Cryptoasset)
The volume of any cryptoasset is the total spot trading volume reported by all exchanges over the last 24 hours for that cryptoasset. Some market pairs are excluded from the sum, denoted by two asterisks (**) on the markets tab, if the exchange does not enforce a trading fee or otherwise offers significant incentives to trade on the market pair. Market pairs with these characteristics are rather susceptible to wash trading, resulting in artificially inflated reported volumes. From our experience, we have found that it is better to exclude these markets to give a better representation of relative trading volumes for the crypto market.