Control means owning a business, not a stock
“When a controlling interest is held, we own a business rather then a stock, and a business valuation is appropriate.”
Investing
Warren Buffett's July 1965 letter to Buffett Partnership partners, one of the letters in Buffett Partnership Letters, 1957–1970.
Investment funds rise and fall with the market
“Last year I mentioned that the performance of these companies in some ways resembles the activity of a duck sitting on a pond. When the water (the market) rises, the duck rises; when if falls, back goes the duck.”
Markets likely rise over time, with interruptions
“In our opinion, the probabilities are that over a long period of time, [the water level] will continue to rise, though, certainly not without important interruptions.”
He would quit if merely floating with the market
“If our performance declines to a level you can achieve by floating on your back, we will turn in our suits.”