The SEC issued a Risk Alert earlier this month that provides some interesting insight into how the SEC conducts its exams. The Risk Alert discusses the SEC's risk-based exam approach, how it selects firms to examine, and how it determines the scope of the exam. Bonus: The Risk Alert includes an addendum that outlines the documents that are typically requested in a regulatory exam.
Although this Risk Alert solely covers the SEC's processes, many states will follow similar processes. And the list of documents is relevant regardless of whether you are SEC- or state-registered. I suggest using this document list to perform a quick review of your books and records to ensure you are retaining all relevant records, and would be able to produce them in the event of an exam.