The securities business is the simplest, followed by funds, and the most difficult is futures. Generally speaking, the preparation for the securities industry takes more than two weeks. If it is a simple exam, you don't need to read any books. Just brush the questions in the question bank. Those online questions are all false. Don't trust them. Funds are not much more difficult than securities. Futures are relatively more difficult and take a little longer to prepare. When buying books, there is usually a group where many people exchange experiences. I hope my answer is helpful to you, and I wish you good luck in the exam.