Your broker charges you for the part of the day the index goes up
Almost all of the rise in a major equity index is earned overnight, and a long index CFD pays financing for every night you hold it. I read two abstracts, not the papers: Strikingly Suspicious Overnight and Intraday Returns (2020) and Does Overnight News Explain Overnight Returns? (2025). Both put the gain in the overnight session.
The retail version pays for the window it captures. The charge is taken at rollover.
The Swap column on the open position in the Toolbox Trade tab is the total; it is negative when it is a cost, so use its size. For a long hold, on the same nights and volume, take the exchange's close and next open (16:00 and 09:30 New York time for a US index), not the daily bar's, and multiply each move in ticks by the tick value and the volume. If that total is smaller than the cost, the hold loses money before the spread.
Run both totals on one index position this week, and keep the hold only if the overnight total is larger than the cost after the spread.
