I've got the information you need to address your concern, Chicks Accounting.

If you transfer funds between two brokerage accounts within the same business, you can record it as a bank transfer in QuickBooks Online (QBO). Moreover, you can create a check or expense in the Day Trading LLC account and record it as a bank deposit in your Ameritrade business account if it's from one company to another.

To create a check or expense:

1. Go to + New.
2. Select Check or Expense.
3. Choose the bank account the funds are coming from.
4. Type in the Payee, Payment Date, and the Payment Method 
5. Under Category details, in the Category column, select an Asset.
6. Enter the amount to be transferred in the Amount column.
7. Click Save and close or Save and new.

To make a bank deposit:

1. Hover to + New.
2. Click Bank Deposit.
3. Choose the bank account the funds are going to.
4. Enter the Date.
5. From the Received From dropdown, select who sent the money. 
6. From the Account column dropdown, select an Equity or a Liability account to reflect the funds coming into the business.
7.  Input the amount you've received in the Amount column.
8. Click Save and close or Save and new.
   
   

I also recommend consulting your accountant to ensure accurate of books. If you don't have one, you can find a professional through this link: https://quickbooks.intuit.com/find-an-accountant/.

Moreover, you can initiate a fund transfer from your bank account to your credit card account, enabling you to manage your financial resources for upcoming obligations efficiently. 

I'm always available to assist you regarding transferring and recording funds in QBO. Just tap the reply button for your response. Best wishes!