A withdrawal lock is applied based on the value of the qualifying securities in the accounts that you selected which have been used as a security for your loan. While you will still be able to buy and sell shares within these accounts you will not be able to transfer or withdraw cash to the value of the lock from these accounts.

This is known as a collateral lock.

The term collateral refers to an asset that a lender accepts as security for a loan. The collateral acts as a form of protection for the lender. That is, if the borrower defaults on their loan payments, the lender can seize the collateral and sell it to recoup some or all of its losses.