Expand NASDAQ : COST Costco Wholesale Today's Change ( -1.26 %) $ -11.97 Current Price $ 940.79 Key Data Points Market Cap $423B Market cap calculated using publicly traded shares outstanding only. Implied market cap may vary. Costco reported net sales of $23.12 billion for the four weeks ending Aug. 2, up 10.7% year over year. Expand NYSE : BRKB Berkshire Hathaway Today's Change ( -1.66 %) $ -8.80 Current Price $ 520.62 Key Data Points Market Cap $1.1T Market cap calculated using publicly traded shares outstanding only. I don't think investors need to bet that Berkshire Hathaway will actually buy Costco shares again to see the opportunity.