If the terms of the loan require transferring collateral to the lender in any arrangement that isn't a multisig where you are a party, then rehypothecation is likely to occur. At best the collateral will be segregated and moved individually and can be observed. At worst it will be mixed into a pool of similar collateral and you won't be made whole when a link in the chain of trust-me-bro fiduciaries goes awry. This isn't new. It's business as usual. Read and understand the terms of contracts before playing the game.