The total value of five Japanese companies in Berkshire Hathaway’s stock portfolio has exceeded $30 billion in recent weeks, and Warren Buffett appears to still be buying their shares, having previously announced he would hold them forever.

Berkshire had already been building its investments for twelve months when Buffett initially disclosed stakes of about 5% each on August 30, 2020, his 90th birthday.

At that time, the total value of the five positions in the Japanese market was approximately $6.3 billion.

The value increased by 392% to reach $31 billion by the end of last week, as Berkshire increased its investments over the years, with shares rising between 227% and 551%.

The total may be higher as some additional purchases have not yet been disclosed.

There have been recent public disclosures that two of the stakes exceeded 10%. One of the companies, Mitsui, disclosed this week the exact number of shares Berkshire owns.

In a press release issued on Thursday, the company reported that Berkshire’s subsidiary, National Indemnity, owns 292,044,900 shares as of September 30.

At Friday’s close, their value was about $7.1 billion.

This represents a 10.1% stake, making National Indemnity the largest shareholder.

It also represents a 2.3% increase from 285,401,400 shares, or 9.7%, announced in March.

This week’s press release follows a statement Mitsui issued two weeks ago, stating that Berkshire informed them it “now owns 10% or more of voting rights in Mitsui,” but had not yet disclosed the exact number of shares owned.

In late August, Mitsubishi reported that Berkshire informed them its stake in Mitsui had increased to 10.2% from 9.7% in March.

Nothing has been heard since March about Berkshire’s other three stakes in Japan — Itochu, Marubeni, and Sumitomo — but it would not be surprising to learn these stakes have also exceeded 10%.

In 2020, Buffett promised companies he would not raise Berkshire’s stakes above 10% without permission.

However, Buffett wrote in his annual letter to shareholders issued in February: “As we approach this limit, the five companies have agreed to moderately relax the cap.” As a result, he said, “Over time, Berkshire’s ownership of the five companies is likely to increase slightly.”

In 2023, Buffett told CNBC he was attracted to the stocks for the first time in 2020 because “they were being sold at what I thought was a high price, especially compared to prevailing interest rates at the time.”

This year, he told shareholders that Berkshire would hold them “for 50 years or forever.”