BlackRock CEO Laurence Fink,
who would likely be Hillary's Treasury Secretary, has been fairly good on position favoring regulation of his own industry. He also has a
pretty populist idea of capital gains tax reform based on length of investment--so day traders would pay really high rates while those who hold onto the investments for 3, 5, or 10 years would pay less, which would favor smaller investors and retirement funds over Wolf of Wall Street types and stabilize the market to prevent recession-starting short term bubble parties.
"Cracking down on Wall Street" is a crock, anyway. A good banking and investment sector is important to our national economic strength. The more important thing progressives should be focusing on is to make sure these rich people are paying a fair income tax and that our poorer citizens have access to affordable education to become recession proof via mobility. We wouldn't be better off if Wall Street were destroyed and everything else the same. There would just be different group of rich people starting gigantic financial bubbles.