Here's a snippet:

Prices can Spiral due to Large Purchases

Consider a trader known for takeover bids. If they begin buying shares of stock in a company, other traders might assume that they plan an acquisition. That could set off a rush to buy the stock, sending its price through the roof and making the takeover far more expensive.

Or consider a company in the middle of a good-faith share buyback. The board is not looking to enrich itself, just restructure the company. Yet as the company begins to buy all of its own shares off the market, the price will spiral, pushing expenses (and potentially debt) higher.

A public exchange would publish all of this information through its central marketplace. Investors would immediately know about the takeover or share buyback in progress and would trade accordingly. On a dark pool, these parties can keep things quiet a little longer and hopefully not get hit with spiraling prices.

https://smartasset.com/investing/dark-pool