A position in your margin account is considered concentrated if it represents 25% or more of your account's long market value and you have a margin loan (debit balance) of over $100,000. Due to this concentration, the maintenance requirement for that security may be set higher than the standard margin requirement to help manage risk.
If the Concentration Requirement for a particular security is higher than the standard requirement, then the requirement for holding that security in your account will be increased.
Note: ETFs are not subject to concentration margin rules.
