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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Another possibility is Ironfish(https://ironfish.network/), but I don't know how much liquidity there exists in either of these. I don't think you could launder/hide $4bn through either of these. Perhaps slowly over a long period of time.
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