Where are the funds held that are used for generating the interest?
Bitcoin used for cryptocurrency trading is held with large, international exchanges like Binance that have a strong reputation for security of funds. Where ever possible the exchange accounts held with these exchanges are exchange accounts belonging to the companies involved with PL so that PL has as much control of the funds as possible. Any Bitcoin not being traded is held in cold storage offline by PL.
Funds held for trading Forex are held in Broker accounts with reputable brokerages where the broker accounts also belong to companies involved with PL so that again PL has as much control of the funds as possible.
Any fiat funds not in trade are held with reputable banking institutions in accounts belonging to companies involved with PL.