Buy-ins required by SEC or SRO rules (e.g., to comply with the close out requirements of Regulation SHO or FINRA Rule 4320, or the buy-in requirement of SEA Rule 15c3-3) must be reported to CAT using the Buy-In handlingInstructions value (BIN).  

Buy-ins originated pursuant to Regulation SHO or applicable SRO rules (e.g., FINRA Rule 4320), whether executed or unexecuted, must be reported by the clearing firm as a proprietary order of the clearing firm with the FDID of the clearing firm’s proprietary account in which the buy-in originated. The order must be reported with the ‘BIN’ handlingInstructions value to indicate the order represents a buy-in. If the clearing firm allocates the buy-in responsibility to a correspondent broker-dealer pursuant to Regulation SHO or applicable SRO Rules (e.g., FINRA Rule 4320(c)), the correspondent broker-dealer must report the buy-in as a proprietary order with the FDID of the correspondent firm’s proprietary account in which the buy-in occurred. The order must be reported with the 'BIN' handlingInstructions to indicate the order represents a buy-in.