 J Sainsbury PLC LSE:SBRY posted a solid set of first-half results but forward-looking investors are concerned about whats in store for the grocer in the months ahead. Shares in the FTSE 100 supermarket group hit a seven-year high this summer as takeover speculation surged, with private equity and Czech billionaire Daniel Kretinsky seen as potential suitors after rivals Morrisons and Asda were snapped up in the past year. 