Jack Ma has been buying up shares in Alibaba, NY Times’ DealBook reports

Alibaba co-founder Jack Ma has largely disappeared from public view, but has been buying up Alibaba shares in recent months, as has Joe Tsai, his longtime business associate and the company’s chairman, Andrew Ross Sorkin, Ravi Mattu, Bernhard Warner, Sarah Kessler, Michael J. de la Merced, Lauren Hirsch and Ephrat Livni write in DealBook’s newsletter, citing sources. According to the report, this suggests that Ma and Tsai believe the business is undervalued. Ma bought $50M worth of Hong Kong-traded stock in the quarter, according to a person with knowledge of the matter, who add that Tsai acquired about $151M worth of Alibaba’s U.S.-traded shares in Q4.