The announcement to the NZX disclosing the loss was made on October 28 - five business days after the board had become aware of it.
The eventual announcement saw QEX's share price drop by 36 per cent.
"The Tribunal considers that a breach of the rules relating to continuous disclosure is a breach of a fundamental obligation," the Tribunal said.
"Compliance with this rule by issuers is essential for maintaining market integrity and investor confidence," it said.
The infant formula heist was not the only problem QEX has faced in recent times.
In March, NZX's regulatory arm, NZ RegCo, announced that it would investigate a statement made by QEX regarding charges that were brought by MPI against the trading subsidiary New Y Trading Ltd and QEX's chief executive Jinjie (Ronnie) Xue.
That investigation was in addition to inquiries commenced by NZ RegCo in October in relation to inventory loss.
NZ RegCo put trading in QEX shares into suspension on February 18 on the basis of QEX's breaches of its corporate governance requirements.
On the same day, former Federated Farmers chief executive Conor English resigned from the board, along with Danny Chan and Martin MacDonald, citing differences with Xue, who is the company's majority shareholder and the sole remaining director.
MacDonald had been appointed independent director just days before his resignation.
QEX listed on the exchange's then small-cap NXT in 2018.
Before its suspension, the stock had traded at 28.5c, having lost 47 per cent over the preceding 12 months.
The Tribunal - a disciplinary body is independent of NZX and its subsidiaries - determines and imposes penalties for referrals made to it by NZX in relation to the conduct of parties regulated by its rules.
