Pros
I've worked at Optiver a long time. Every year it gets better. - The company is managed on the basis of principles and values, not process or politics. - Those principles and values align very nicely with mine: -- Autonomy: there is very little hand-holding and extraordinarily high expectations of individuals in the company. The company rewards those that keep pushing those expectations higher with greater responsibility and authority. -- Collaboration: there are a lot of great fights over the right way to approach a given problem. When we're at our best, everyone in the fight has a strong opinion but is also listening to everyone else and continually re-evaluating that opinion as new information, ideas, and opinions are expressed. -- Prudence: the company carefully evaluates risk/reward trade-offs both when it comes to trading and technology decisions. The latest fads (cryptocurrency, esoteric programming languages, etc) are carefully evaluated, but reckless pursuit of them is frowned upon. I'll end with a sports analogy. Working at Optiver Chicago is like playing for the Patriots or the San Antonio Spurs. It certainly isn't for everyone. But if you like competing for the championship every year and always pushing yourself to be better, there's no better team to join.
Kontras
If the company values do not align with yours, you will find it an increasingly frustrating place to work. Honestly, just read the cons from other posts and you can see how that plays out. If you find the principles above strange, out of fashion, or backwards, you'll agree with other people's cons. If you think those principles are refreshing, you will have a hard time coming up with many cons.