You'd think that Bala Cynwyd-based equity options trader Jeff Yass might want to sit out the rest of 2015 when it comes to campaign contributions. After all, it was just this spring that the Montgomery County billionaire -- along with two of his partners in the Susquehanna International Group, Arthur Dantchik and Joel Greenberg -- invested $7 million or so in a political action committee to make state Sen. Anthony Hardy Williams the next mayor of Philadelphia. Instead, Williams and his libertarian-approved brand of charter-school boosterism were soundly rejected by voters in a landslide Democratic primary win for the now-mayor-elect, Jim Kenney.