Check out the companies making headlines after the bell Monday:
DuPont shares jumped more than 5 percent after the chemical company said its CEO and chair, Ellen Kullman, would retire, effective Oct. 16. DuPont also lowered its operating earnings outlook for the full year, citing a strengthening dollar and weaker agricultural markets.
Shares of health technology firm Illumina plunged 15 percent in extended trading after the company projected lower-than-expected revenue for the third and fourth quarters.
Arena Pharmaceuticals shares were up nearly 5 percent after announcing that CEO and President Jack Lief will retire at the request of the biotech company's board.
General Mills shares inched lower after the packaged-goods producers recalled 1.8 million boxes of gluten-free Cheerios cereal because they could contain an undisclosed allergen — wheat.
The Container Store slipped about 4 percent after it missed second-quarter earnings and revenue estimates. Its comparable-store sales surprised to the upside.