Use of "own" accounts in FinLib

I have been reading the FinLib tutorial lib-finance/Tutorial.daml at 0b21a0723db01f63f7d6b16ed59ea8d37030219f · digital-asset/lib-finance · GitHub. I notice that in script5 Alice’s deposit is transferred to Acme’s “own” account. As a result a new Asset contract would be created in Acme’s own account. What would be the purpose of keeping this Asset contract around? Since the asset has now be transferred to another bank, should this contract be archived?

Are you referring to these lines?

digital-asset/lib-finance/blob/0b21a0723db01f63f7d6b16ed59ea8d37030219f/model/src/DA/Finance/Tutorial.daml#L224-L227

      
        

            
aliceToAcmeDepositCid <- submit alice do
            
  exerciseCmd aliceSettlementCid AssetSettlement_Transfer with
            
    receiverAccountId = acmeOwnAccountId
            
    depositCid = aliceDepositCid
        
      
    

You are correct, assets in one’s “own account” can be removed.

Technically, this is possible due to the party being both, the provider and the owner of the deposit. So they have the authorization to archive the contract.

Economically, such a deposit represent a liability of the provider against itself, so it can be safely remove without effect on the balance sheet.

You can think of an investor “sending back” to the provider as giving up a deposit. That is, it represents a debit from their account. A deposit represents a liability for the provider, and an asset for the owner. After sending it back to the provider it therefore represents a liability of the provider against itself and can be removed.

Similarly, creating an asset it one’s own account, and sending it to a party represents the crediting of an account.

The reason it is modeled that way is that it fits well with the settlement contracts (ie. SettlementInstruction) and we don’t need to model separately the crediting and debiting of accounts.

Yes that’s right. Apologies, should have put a link to that code in my question.