Bank of America CEO Brian Moynihan doesn’t know why Warren Buffett’s Berkshire Hathaway is selling

Buffett’s support of BofA goes back more than a decade, starting when he purchased $5 billion worth of stock in 2011.

At the time, the purchase was a much-needed vote of confidence in the banking sector following the 2008 financial crisis, but the deal has also netted the Oracle of Omaha healthy returns.

Buffett told Fortune he dreamt up the deal while in his bathtub, and following a call with Moynihan bought 700 shares for $7.14. Shares of BofA now trade at $39—an increase of more than 446%.

Moynihan and Buffett’s relationship has been one of trust from the start, with the banking tycoon reportedly conducting the $5 billion deal in near-total secrecy until it was voted through by the board.

But it appears Moynihan isn’t privy to Buffett’s latest tactics—and more importantly, he can’t ask.

Berkshire Hathaway this week offloaded yet more shares in the Charlotte-based bank.

Per a SEC filing, on Tuesday Berkshire disclosed it has sold about 5.8 million BofA shares worth $228 millio between Sept. 6 and Sept. 10.

The deals conducted since the summer have reportedly earned Berkshire $7.19 billion, Reuters reports.

On the heels of the latest sale, Moynihan praised Buffett. He told the Barclays Annual Global Financial Services Conference this week: “I don’t know what exactly he’s doing because, frankly, we can’t ask and we wouldn’t ask.

“The market is absorbing the stock and it’s a portion of the volume every day, and we’re buying the stock—a portion of the stock—and so life will go on. But he’s been a great investor for our company and stabilized our company when we needed it at the time.”

BofA’s share price has indeed stayed stable despite the selloff, and over the past six months shares were up 8.5% at the time of writing.

Moynihan and Buffett

Despite the selloff Berkshire still holds an 11% stake in the company, making it BofA’s largest individual shareholder.

This figure may be notable, and give a hint as to why the conglomerate might be selling. If Berkshire’s share dips below 10% then it will be below the threshold for regulatory scrutiny.

While some analysts believe it’s a play for privacy, others believe it signals a battening-down of hatches.

Haruki Toyama, portfolio manager and head of the mid and large cap team at Madison Investments, noted that when Berkshire—which has a $977 billion market cap—has historically increased its cash position, it has signaled rocky times ahead in the economy.

“If you go back, the last time [Berkshire] had this much cash relative to book value was before the financial crisis,” Toyama told Fortune. “So you can make the case that maybe [Buffett is] thinking a little bit more about risk.”

Berkshire Hathaway did not immediately respond to Fortune’s request for comment.

Whatever the motivation, Moynihan and Buffett have consistently lauded each other’s leadership.

Buffett told CNBC last year he likes Moynihan “enormously” while Moynihan has called the man worth $145 billion the “smartest investor in the world.”