Yes. Alpaca Securities LLC, a member of the Securities Investor Protection Corporation (SIPC), serves as the sub-custodian for your securities account for US-listed securities only.
In the event that a SIPC-member fails and is placed in liquidation under the Securities Investor Protection Act, SIPC protects the securities customers of its members up to $500,000 (including $250,000 for claims for cash).
However, kindly note that SIPC does not protect against any decline in the value of your securities. For more information, please refer to www.sipc.org.