What are authorized participants?
The institutions allowed to create and redeem ETF shares directly with the fund.
Authorized participants (APs) are broker-dealers that have signed agreements with an ETF's distributor allowing them to create and redeem shares directly with the fund. Most large ETFs have dozens of APs; well-known examples are the major market-making and investment banks.
APs are not paid by the fund and have no obligation to act — they participate because arbitrage between the ETF's price and its underlying basket is profitable. Their competition is what keeps spreads tight and prices near NAV.
The health of the AP ecosystem matters most in stressed markets: if arbitrage becomes risky or the underlying market seizes up, premiums and discounts can widen until normal conditions return.