Southeastern Conference
An athletic association. USA. Compare: PAC-10, Big 12, Big 10, ACC, Big East, dozens more.
It’s a sports thing. Kind of like a league.
I hope I’m not being whooshed. 
No, Zeldar, you weren’t being whooshed. I am Canadian, and not at all interested in most kinds of American sport. I may have heard, but never noticed or absorbed the acronym before.
Okay. Thanks for the info.
The Securities and Exchange Commission. They regulate securities markets in the US.
Yep. That’s another one. You have to have a context. The OP mentions some states, so that might cut down on the confusion, if it pops up.