Yes, there are always costs related to forex trading. Even if you are in and out of the market quickly while day trading and exit your trades before the rollover at the end of each trading day, you will still cross the spread or bid/ask prices on each trade, in addition to any per-trade commissions. For example, even if you have a commission-free account, when you place an order to buy currency, the asking price will always be higher than the bidding price if you were to sell again at that exact moment. In other words, once your order to buy is executed at the asking price, the trade is already at a loss for the amount of the spread, which must be overcome to either break even or turn a profit. For these reasons, it’s crucial to factor your trading costs into your strategy, especially for more cost-sensitive trading strategies. This will be true over time even on a so-called zero spread account since on average, after many trades, costs will still add up despite paying close to zero spreads.