Alternative Asset Managers deserve their own topic. There are many flavors here, but these firms specialize in managing and investing in assets outside of traditional stocks and bonds. Things like private equity, hedge funds, real estate, infrastructure, commodities, venture capital, and more.
Several public ally traded names:
BX, ARES, APO, KKR, BN, CG, HLNE, OWL, MC, PX, TPG
I am sure there are more, and firms like GS, Morgan Stanley, Blackrock and other banks dabble in alternatives.
I have owned KKR, BN and APO for 10-15 years. These companies have been good to me.