Pros
I worked with some really great and competent colleagues. There are some awesome people, which is (was?) their greatest asset in my humble opinion.
Cons
Changing the company on Glassdoor is an obvious con and a way to hide their previous reviews. See ION Trading (vs ION Group) for the real reviews This is typical of the way top management would operate, they would do whatever it takes to make things appear rosy. I joined ION as part of an acquisition, and from that point things started going downwards. As per other reviews, communication from top management is non existent. Costs are being cut to the bone, to the point where they were just maintaining our product and the team was shrinking. I understand cost cutting is needed, especially after an acquisition, but in two years it was relentless. Most of the good people left by that time, so why acquire a company, just to then let it go like that?