By Svea Herbst-Bayliss (Reuters) -Billionaire investor Ryan Cohen said on Sunday he now owns nearly 10% of Bed Bath & Beyond and wants the housewares retailer to explore strategic alternatives that include a full sale of the company. Cohen, who co-founded online pet products retailer Chewy and is chairman of the board of videogame retailer GameStop Corp, criticized Bed Bath & Beyond, which is worth roughly $1.6 billion, for an “overly ambitious” strategy, overpaying its top executives and failing to reverse market share losses. “We believe Bed Bath needs to narrow its focus to fortify operatio…