Alright, let's do this again:
SEC = Civil
If SEC finds criminal activity they kick to
DOJ = Civil + Criminal
By the time DOJ subpoenas are served civil is known.
Goal of civil is to get enough information to indict on criminal through a grand jury.
By the time DOJ subpoenas are served the target(s) of the criminal investigation have already had their trash dug-through by FBI agents for months.