Dark pools exist largely to prevent HFT from parasitically extracting value from large trades. Spearing whales I believe it&#x27;s called. Giant investment banks, hedge funds, insurance companies and <i>pension</i> funds use them.<p>&gt;That if we didn&#x27;t have HFT, we wouldn&#x27;t need them? That&#x27;s an argument for HFT, not against.<p>Dark pools are an evolved defense against parasitic market players that is not cheap. These costs are then passed on to you via your pension fund, index fund or if you buy insurance.<p>I don&#x27;t see how that&#x27;s an argument for them unless you or your friends were personally profiting from it.