Here come the bearish analyst comments on Alibaba

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After being up as much as 4.5 percent Tuesday, Alibaba shares reversed sharply to down 2 percent midday on cautious comments from the head of investor relations, Jane Penner, at Citi's Global Technology Conference.

What she said has already caused one analyst to cut earnings estimates and price forecasts. More are likely to follow, which could weigh on the shares this week.