Does “Commission-Free” Mean the Trade Has Zero Transaction Cost?

No, "commission-free" does not mean the trade has zero transaction cost. While the explicit commission charged by the broker is zero, the trade still incurs implicit costs.

The primary implicit cost is the bid-ask spread, which is the difference between the buy and sell price. Additionally, the execution price may be less favorable due to the broker's use of Payment for Order Flow (PFOF).

Other minor costs, such as regulatory fees, may also still apply.