Stock in Alibaba the Chinese e-commerce site, fell 7% in Hong Kong trading on Monday after reports the company is moving its headquarters out of the country. Alibaba (ticker: HK:9988) is close to completing a new campus in Singapore, according to the reports, which could become its global headquarters. The Sina Financial news site reported that the company denied the speculation and its headquarters would remain in the city of Hangzhou in the east of mainland China.