Hi all, I keep getting confused. There are two ways I can trade, one is spot and the other is forwards. Trading spots and holding positions for more than a few days necessitate the need for adjusting for the carry effect. Trading forwards at a flexible time horizon necessitate the need for constructing a continuous contract with daily Mark-to-market. I suspect the above two constructed time series are the same. But I haven't thought thru yet. Anyway, after you have these constructed/stitched time series, you generate signals and run backtest on top of these time series. And then what really do you trade? Spots or forwards? Or doesn't matter? And then you calculate the PNL based on these constructed/stitched time series? Any thoughts? Please shed some lights on me on these! Thank you!