Earlier quoted context omitted.
A case could be made though that it is OpenAI who is operating illegally, attempting to corner the market.
There is nothing suspicious or abnormal about this behavior. It is called competition. Ironically, trying to prevent this kind of behavior prevents competitiob, and is a key factor for causing monopolization
If they bought the DRAM in order to stop their competitors from using it because they are falling behind, that's anticompetitive in spirit, though I'm not sure if it actually breaks any laws.