The term 'Big Seller in Bear Markets' can be summarized by two crossword solutions: POOH (4 letters) and TEDDY (5 letters). POOH is the lovable bear character created by A.A. Milne in 1926, who has since become a beloved figure in children's literature. TEDDY is a common nickname for Theodore Roosevelt, the 26th President of the United States, who was known for his strong leadership during economic downturns.