In 2020, it was reported that Berkshire Hathaway had sold its entire stake in the Taiwan Semiconductor Manufacturing Company (TSMC), one of the world's largest semiconductor manufacturers. The reason for this decision was not explicitly stated by Buffett or his company, but there are several possible explanations for why he may have made this move.

One possible reason is that Buffett may have been concerned about the impact of the ongoing trade tensions between the United States and China on TSMC's business. TSMC is based in Taiwan, but it has significant operations in mainland China and depends on Chinese demand for its products. If the trade tensions escalated and led to reduced demand for TSMC's products, this could have a negative impact on the company's stock price and earnings.

Another possible reason is that Buffett may have decided to sell TSMC shares in order to free up capital to invest in other companies that he believes have greater growth potential. As a value investor, Buffett typically looks for companies that are undervalued by the market and have strong long-term prospects. If he felt that there were other opportunities available that offered better returns, he may have decided to sell his TSMC shares and allocate his capital elsewhere.

It's important to note that these are just speculative reasons, and without more information from Buffett or Berkshire Hathaway, it's impossible to know for sure why they decided to liquidate their TSMC stake. Additionally, it's important to remember that investment decisions can be influenced by a variety of factors, including personal beliefs, market trends, and changes in the broader economic and political landscape. Therefore, it's always important to conduct thorough research and analysis before making any investment decisions.