While the official reason for their existence is to provide this stability, this secrecy creates a dangerous, two-tiered system. It allows for predatory trading and means the public stock prices you see don't always reflect the true supply and demand because a huge portion of activity is happening in the shadows. Ultimately, it reveals that the market isn't the level playing field you're taught it is, giving a significant, hidden advantage to the financial elite. 

• Real-world cases highlight both sides. In 2014, Barclays faced allegations of allowing high-frequency traders to exploit its dark pool, a case that led to reforms and tighter oversight. 

• Credit Suisse later paid fines for failing to fully inform clients about how its pool functioned. On the other hand, many legitimate institutions use dark pools daily without controversy, viewing them as a necessary tool for efficient, large-scale trading.

In short, dark pools aren’t inherently “good” or “bad”, they’re a complex part of modern market infrastructure. They provide genuine benefits for stability and liquidity, but their secrecy means they require careful oversight to ensure fairness for all participants.