I am no fan of Trump, but that's not strictly true.  Most middle class people have at least some investment.  All workers pay into CPP, which also relies on market returns for sustainability.  And even the very poor see some benefit from rising markets -- it is a factor in job creation.

I am not saying this means policy should favour corporations above people.  But a healthy economy is good for everyone, and a rising market is one of dozens of health indicators.