Does my son need to file a return?

My son is 19 years old and a full-time college student.  He had no earned income during 2020 since the pandemic curtailed part-time work opportunities.  He did have distributions from his 529 Plan (529 of Alaska) paid directly to his university for tuition, fees, etc (totaling about $11k).  His university has generated a 1098.  He also had a few stock transactions in Robinhood.  He filed a return in 2019 since he worked part-time that year.  Does he have to file a return for 2020?