I would argue that dark pools do less to the market than a PIPE deal. We just don't know all the dark pool trades and I'm okay with that. I don't want someone dumping 5 million shares in a hurry if they need out, just let them match a buyer behind the scenes. However, when a bank/hedge fund/private investor jumps into a stock at a discounted price in PIPE deal we all know the price (if it was a registered deal) they bought shares at so it effects the market right away.