SEC | Division of Trading and Markets, 14 Mar

• Broker-dealers should collect margin from counterparties to the fullest extent possible in accordance with any applicable regulatory and contractual requirements.
• Concentrated positions of prime brokerage counterparties pose particular concerns. Staff urges broker-dealers to seek sufficient information to determine counterparties' aggregate positions in any markets that may experience liquidity concerns and work with the counterparties to mitigate risk.
• Staff urges broker-dealers to stress test positions with the proper severity in light of current events and potential market movements, and act to manage the risk of the positions, particularly those that are concentrated, appropriately.
• Staff urges broker-dealers to monitor risk management limits, calibrated to the financial resources of the broker-dealer, closely intraday and escalate any breaches promptly to senior management.