UofT has published a document called "Sources of Government Financial Support During Covid-19 - A Guide for Graduate Students." the first section states that grad students will most likely not be eligible for CERB under current regulations: ...

https://www.artsci.utoronto.ca/sites/default/files/Sources%20of%20Government%20Financial%20Support%20During%20COVID-19%20%E2%80%93%20A%20Guide%20for%20Graduate%20Students.pdf

"Based upon current eligibility rules, the majority of graduate students will generally not qualify for support through the two primary income relief programs: the Canada Emergency Response Benefit (CERB) and Employment Insurance (EI)..."

"...These programs apply to workers who had, and lost, all employment or self-employment income as a result of the COVID-19pandemic, through job loss, illness/quarantine,or caregiving obligations..."

"... If you cannot demonstrate total employment income loss, it is unlikely that you will qualify. This applies in particular to students in the funded cohort, who are currently receiving TA, RA and [UofT] Fellowship (UTF) support, as well as students who hold external grants..."

"...The Government of Canada has acknowledged that postsecondary students are currently left out of these government aid programs and has signalled that they are exploring supports specific to this group."

the document will be updated as new information surfaces