Warren Buffett Watchers Should Tune In. Berkshire Is Lifting Veil on Stock Moves.

What were Warren Buffett and his colleagues at

Berkshire Hathaway

up to with their $350 billion equity portfolio last quarter? Investors will find out very soon.

A regulatory filing expected Tuesday should lift the veil. Investors will be focused on whether Berkshire Hathaway (tickers: BRK/A, BRK/B) added to its stake in

Taiwan Semiconductor Manufacturing

(

TSM

), as well as whether the company continued to pare its longtime interest in

U.S. Bancorp

(USB).