Here's what I do: random long strings as answers for each question, and save them with the credentials in KeePass. That way I keep track of each one, and they can't be used against me.
However, beware of tradeking as an online trading service. They have the lowest rates, but they have some ridiculous backward security requirements.
1) You have to enter passwords with an on-screen keyboard. Which means long complex computer generated passwords are a pain.
2) They present security questions in multiple choice form. That's right, your clever or unique answers are right there easily identified next to all the mundane answers.
Honestly I don't know how they haven't fired their whole security team. I know this kind of security theatre is costing them business, and I bet their back end reflects similarly poor decisions. I am surprised they don't have regular compromise reports.
For the record, I'm much happier with Interactive Brokers: https://www.interactivebrokers.com/
Except that I'd imagine if the thieves in question had access to a person's history and credit report, they would have been able to answer these same questions with greater accuracy than the person whose data was stolen.
For all the effort some companies place on security, it seems wasted when they rely on information that is publicly available--or in this case, part of a corpus of data that may or may not have been stolen.
They understood it was more secure though.