| 2024-01-23 | Sale | Costco Wholesale Corporation COST | director | 8,000 0.0018% | $685.93 | $5.49M | +6.6% | |
| 2018-10-30 | Sale | Costco Wholesale Corporation COST | President and CEO | 22,000 0.005% | $225.60 | $4.96M | +8.19% | |
| 2018-10-29 | Sale | Costco Wholesale Corporation COST | President and CEO | 23,000 0.0052% | $221.52 | $5.09M | +10.67% | |
| 2015-03-13 | Sale | Costco Wholesale Corporation COST | President and CEO | 8,368 0.0019% | $149.25 | $1.25M | -0.31% | |
| 2015-03-12 | Sale | Costco Wholesale Corporation COST | President and CEO | 40,000 0.0057% | $93.47 | $3.74M | -0.4% | |
| 2015-03-11 | Sale | Costco Wholesale Corporation COST | President and CEO | 40,000 0.0058% | $93.42 | $3.74M | +1.01% | |
| 2015-03-10 | Sale | Costco Wholesale Corporation COST | President and CEO | 40,000 0.0058% | $93.87 | $3.75M | +0.44% | |
| 2015-03-09 | Sale | Costco Wholesale Corporation COST | President and CEO | 40,000 0.0057% | $94.86 | $3.79M | -1.27% | |
| 2014-03-14 | Sale | Costco Wholesale Corporation COST | President and CEO | 82,888 0.0124% | $74.36 | $6.16M | +11.14% | |
| 2012-12-17 | Sale | Costco Wholesale Corporation COST | President and CEO | 120,000 0.0274% | $98.21 | $11.79M | +13.69% | |
| 2012-03-12 | Sale | Costco Wholesale Corporation COST | President and CEO | 75,000 – | $0 | $0 | +8.46% | |
| 2011-04-11 | Sale | Costco Wholesale Corporation COST | President and CEO | 35,200 0.0036% | $34.28 | $1.21M | +8.29% | |
| 2010-03-11 | Sale | Costco Wholesale Corporation COST | President and CEO | 37,500 0.0085% | $60.00 | $2.25M | +2.63% | |
| 2009-02-09 | Sale | Costco Wholesale Corporation COST | President and CEO | 50,000 0.0094% | $36.91 | $1.85M | +9.6% | |
| 2009-02-06 | Sale | Costco Wholesale Corporation COST | President and CEO | 50,000 0.0094% | $36.91 | $1.85M | +9.33% | |
| 2008-01-31 | Sale | Costco Wholesale Corporation COST | President and CEO | 65,000 0.005% | $22.88 | $1.49M | -4.14% | |
| 2007-02-13 | Sale | Costco Wholesale Corporation COST | President and CEO | 54,500 0.0029% | $13.44 | $732,344 | +8.07% | |
| 2007-02-02 | Sale | Costco Wholesale Corporation COST | President and CEO | 15,500 0.0035% | $56.37 | $873,689 | +8.14% | |
| 2004-11-02 | Sale | Costco Wholesale Corporation COST | President and CEO | 27,000 0.001% | $8.75 | $236,250 | -5.19% |