The SEC has issued new guidance for broker-dealers regarding the custody of crypto asset securities. This guidance clarifies that these firms must maintain "physical possession or control" of customer assets, which means they need exclusive access to the private keys for these digital tokens. The SEC defines “crypto asset securities” to include tokenized versions of traditional equity or debt securities, an area gaining more regulatory focus under SEC Chair Paul Atkins. Broker-dealers are now required to implement robust systems to protect private keys from theft or loss. They must also have written policies in place and be proactive about potential operational risks. If a broker-dealer knows of any significant security issues or risks associated with the blockchain technology they use, they cannot claim they have possession of the crypto asset securities. Moreover, firms need plans ready to tackle issues like blockchain malfunctions or network attacks, ensuring compliance with legal orders that may affect customer assets. This guidance responds to market participants' requests and acts as an interim measure while the SEC continues to refine its approach to crypto regulations. The emphasis on maintaining control over private keys and being prepared for technological disruptions highlights the SEC's commitment to protecting investors in the evolving digital asset space.