Major U.S. indices are trading in positive territory. But not shares of General Mills. The maker of Cheerios disappointed by missing Wall Street's estimates for its fourth-quarter earnings. General Mills' stock is down significantly in midday trading. Barnes & Noble also missed earnings estimates, but that's not the story investors are watching. The bookstore chain is beginning a new chapter, spinning off its Nook business as a separate public company in an effort to boost shareholder value. Investors are welcoming the news, moving the stock much higher Wednesday. TheStreet's Susannah Lee has the details.