20,000,000 USD is very large and can buy Bitcoin around 363.64 Bitcoin at the price rate of 1 Bitcoin = 55,000 USD.
The value is very large and I believe ALIBABA has its own purpose to buy Bitcoin on a large scale because it is certain that the company name when issuing the money must have income or profit.
The main purpose of this ALIBABA is indeed a secret, but I believe that one day ALIBABA will open wide to the cryptocurrency space, just like Jack Ma who supported Justin Sun to create TRON. This is only my opinion and not financial advice .