Intel Corp. (INTC) CEO Brian Krzanich sold off a large portion of his stake in the chip maker before the public was made aware of a significant security vulnerability in its flagship PC processors.

According to a report from The Register, Krzanich and Intel were informed by Alphabet Inc.’s (GOOGL) Google that the company’s processors were vulnerable to password and other data theft in June. In November, Krzanich then sold shares worth millions of dollars, months before the public found out about the design flaws. 

A filing with the Securities and Exchange Commission, reported on by Business Insider, showed that Krzanich sold 245,743 shares of stock he owned outright and 644,135 shares he received from exercising his options. Combined, the transactions made November 29 netted him a reported $24 million.

The sale was made as part of a 10b5-1 plan, a rule that enables directors to execute future stock transactions at a predetermined time to avoid facing accusations of insider trading. Krzanich adopted the plan October 30. By then, he was aware of the vulnerabilities in the company’s processors, a revelation that the public only found out about this week. Intel’s stock experienced its worst day in months when news about its chip flaw went viral on Wednesday.

The timing of Krzanich’s large transaction attracted plenty of criticism. Directors are legally required to refrain from buying and selling stock when they possess sensitive information outside of the public domain. The fact that Krzanich only kept 250,000 shares, the minimum requirement as part of his employment agreement, has fueled further skepticism that the sale might have been motivated by his knowledge of Intel’s design flaws. (See also: Intel Will Take More Risks, Says CEO in Internal Memo.)

In a statement, an Intel representative refuted claims that Krzanich's big trade was linked to the company’s chip vulnerability, adding that the transaction was executed as part of a standard stock sale plan. "Brian’s sale is unrelated," the representative said in the statement, according to Business Insider. "He continues to hold shares in-line with corporate guidelines." (See also: Chip Stocks Start Year Strong on Upbeat Nov. Data.)


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