Has anyone tried them for backtesting? What are the pros and cons when compared to backward adjusted data?

You cannot perform backtests on ratio-adjusted data.


If you wish to perform backtests, you can use

-> single month contracts and adjust for spread and rollover gains or losses
-> standard backadjusted contracts and adjust for rollover spread (basically no adjustment)


Ratio-distorted backtest

If you use ratio-adjusted data for backtesting, you will simply get (completely) false results, as all gains or losses for the old contracts are ratio-distorted.

Fat Tails 

You cannot perform backtests on ratio-adjusted data. If you wish to perform backtests, you can use -> single month contracts and adjust for spread and rollover gains or losses -> standard backadjusted contracts and adjust for rollover spread (basically no adjustment) Ratio-distorted backtest If you use ratio-adjusted data for backtesting, you will simply get (completely) false results, as all gains or losses for the old contracts are ratio-distorted.

Thanks but why are so many using them? Are they - let us say - misguided?

solotrader 

Thanks but why are so many using them? Are they - let us say - misguided?

Not everybody wants to perform a backtest.

And who tells you that many people use ratio-backadjusted charts? I have never seen one so far.