When Warren Buffett was managing his early investment partnerships in the 1950s and 60s, he sought deeply undervalued securities for his portfolios. This approach is commonly referred to as deep value investing, although I believe characterizing the young Buffett's style as value is a mistake.
More often than not, Buffett took controlling positions in businesses and then used his position as a majority stockholder to unlock value. This approach seems more activist than passive value investing. He also acquired prominent positions in companies going through some sort of significant change, a change that would ultimately unlock value.
To put it another way,...
