I've been using IB to trade futures for a while now, but lately I've been flirting with the idea of swing trading equities on the side to see if my intra-day strategies translate to longer term trades. I want to do this as an experiment and use very small dollar amounts, which means most trades will be odd-lots lower than 100 shares. As an experiment to see what I would be paying in commissions on these trades using the unbundled cost structure, I bought 1 share of GLD yesterday before the close. The execution report told me I paid $0.70 in commissions, which was expected, since the IB website says the following on the unbundled US equities page: "For US orders, USD 0.7 minimum per order, only the bundled fee structure is available for Non-Smart Routed API orders." This morning I sold that 1 share of GLD, and the execution report said I pad $0 in commissions. My order was executed on BATS. I double checked my account equity and confirmed that I was not charged a commission for the trade. For those who have experience with IB's unbundled equities structure, why didn't I pay the minimum $0.70 commission on that trade? Are buys treated differently than sells? Does it have something to do with the exchange it was executed on?