Groupon, Inc. (GRPN) has seen its stock decline 25.2% year to date (YTD) against the Zacks Internet-Commerce industry’s growth of 22.9%, the broader retail sector’s return of 19.4% and the S&P 500 index’s rally of 20%.GRPN, which has emerged as a two-sided global marketplace company, has been suffering from its weakening momentum in the international market. Unexpected site stability issues related to its cloud migration project have also been heavily affecting the company’s performance.Groupon’s business m ...