Prime brokerages use its VAR model to set margin requirements for hedge fund clients.

FORBES: Risks

That includes JPMorgan which set a January 31, 2012 deadline for automating its VaR model and then apparently forgot about it.

FORBES: Solutions To Spreadsheet Risk Post JPM's London Whale

Another Supervisory Letter cited deficiencies with VaR Model Risk Management.

FORBES: No Accounting For Auditor PwC At Levin's Whale Hearing

When the mark-to-market loss on the derivatives was disclosed, JP Morgan restated VaR to be roughly double the previous claim, using a different, older model.

FORBES: Did JP Morgan Violate the Volcker Rule?