ERROR 43: Variable stops are not supported in rotational and raw backtest modes

AmiBroker
1

Hi,
Would somebody be so kind and point me in the right direction?

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For ranking purposes I'm using BacktestRegularRaw.
The Applystop function works for %-based stops, however, it doesn't work for point-based stops.

I understand how the backtester works, i.e. collect signals first, then apply portfolio constraints (Cash, maxlong, etc.)

If somebody could be so kind and help me understand:

  1. Why is ApplyStop not working for point-based stops in Raw/Rotational backtest modes, but for %-stops. Could someone elaborate?
  2. How can I program a max stoploss based on points (for futures, FX) when using RAW backtest mode. Unless I'm missing something, I'm off to CBT in low-level using ExitTrade method. Is there another way?

Any pointers would be greatly appreciated. All threads that I found have not yielded results, incl. of the old YAHOO forum.

Thanks.

Dio

2

Could you elaborate on that a bit? BacktestRegularRaw gives you some control over which signals AmiBroker filters out before running the backtest. How do you see it relating to ranking?

3

Thanks for your consideration Matt.

Here's the background:

  • Trend-following / absolute momentum portfolio, consisting out of several futures
  • generate state signal buy, which will remain "buy" unless "sell" is triggered (via flip function)

Some example case:

  • portfolio risk is allocated, no more buy signals are taken (lack of funds, max risk etc.)
  • in the meantime, some more symbols flip to buy or are still in buy, however not taken (lack of funds, etc.)
  • one position exits, funds are available
  • which one is "best" to take (via my PositionScore / ranking)?

With BacktestRegular, this can't be simulated as redundant signals are removed.
Hence BacktestRegularRaw.

With futures (different point values etc) I would like to implement a simple max loss stop, i.e. 3*ATR(20). As the stop is point based, I get the above error. Now, there is nothing wrong with the error per se, it's in fact implemented in such a way.
I'm looking for a workaround to implement point-based stops in BacktestRegularRaw, and if anyone has played with it already, maybe someone can shed light on why it was implemented (Error 43) this way because I currently don't understand it.

Thanks for your time.

4

Just to add some more thoughts:
I can pass the 3*ATR(20) to CBT via a static variable and use Openpos.GetPrice to set the fixed stop when the position is actually entered. However, the exit cannot be implemented during the 1st backtester phase, meaning I would need to call ExitTrade from low-level backtest. I'm not sure if my explanation is clear, but it would mean I need to use low-level backtester.

The baseline is I don't know the exact entry in advance working on SIGNAL level, only in the second phase of the backtest can I implement my initial stop because then I know my entry.

5

Your conclusion is wrong i.e. you are mixing up things here. ApplyStop does work without error messages for both percent and point based stops in that backtest mode.

Look here if using fix amount then there isn't Error 43 for all stop modes.

SetBacktestMode( backtestRegularRaw );

Buy = Cross( Close, MA( Close, 20 ) ); 

Sell = 0;

ApplyStop( stopTypeLoss, stopModePoint, 10, True  );

So it is not about percent and point modes but it is about amount argument not being accepted to be array in backtestRegularRaw and rotational BT. So you would get error in both stopModePoint as well as stopModePercent etc. if third argument of ApplysStop is type array (-> variable stop).

You have to ask developer for exact reason.

Other than that you may write custom stop via loop.

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6

Thanks fxshrat.
I get the idea that in BacktestRegularRaw the 3rd argument of Applystop has to be anumber, not an array.

When you say

Sure, but I can't do that on a symbol level because I don't know the exact entry which will be determined in the 2nd phase of the backtest only.
Pls I stand corrected, but other than a low level implementation, I don't see another way, do you?
Thanks. Dio

7

Based on what you have described, I believe you are correct that you will need to use the CBT to enforce your stops.

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8

It is simple, you specified ATR( 20 ) as a "amount". This means that the amount changes on bar-by-bar basis. backtestRegularRaw does NOT allow stops that vary on bar-by-bar basis.

If you want to use stops that vary on bar by bar basis you must use backtestRegular mode or (alternatively) use code written in the Knowledge Base instead
http://www.amibroker.com/kb/2007/03/24/how-to-plot-a-trailing-stop-in-the-price-chart/

It has nothing to do with point or percent. It is all about the fact that you are using backtestRegularRaw together with bar-by-bar changing amount.

backtestRegular is the default mode and should always be used as it is a whole lot faster than other modes.

9

Thanks for your consideration, but your link is not the solution for BacktestRegularRAW.
It's the solution for BacktestRegular instead.

sry, but the code in the library does NOT help in this case, because I do not know the exact entry in the 1st phase of the backtest.
Also as explained, BacktestRegular does not have the desired behavior for my scenario.

Is there a reason why the RAW mode is not compatible with variable stops?
I'm asking because I do not want to re-invent the wheel. Currently I will need to implement low-level CBT to use a variable stop-loss for BacktestRegularRaw.

Thanks for your time reading this.
Dio

10

You answered your question yourself - bar-by-bar changing amount is not available in backtestRegularRaw for the reason you just wrote - you don't know the exact entry and you can't process stops in first phase. Second phase uses fixed amount simply because you would run out of memory in many cases if you passed stop amounts for ALL symbols and ALL bars and ALL stop types (unless cases when you run on very small baskets, but AmIBroker is not for small baskets, AmIBroker runs tests on whole market which often exceeds 50000 symbols). Now if you run 50K symbol basket, 1M data points, 5 stop types, 4 bytes per float you would need 1000 GB of RAM just to store "stop amount".

3 Likes
11

Thanks Thomas, I get it.

Futures portfolios tend to be smaller ~120 symbols max with even fewer traded. I'll give the low-level implementation a shot. I'll post back when ready.

Thanks for your consideration.
Dio

1 Like
12

Hi Tomasz,

I have tried using the number '5' as an "amount" for both Percent and Point based stops in rotational mode - both of them produce output which is not consistent in either percentage or point amounts in the backtest results.

Is there a way to use stops consistenyl in backtestRotational which works or are accurate stops just basically not available at all for rotational backtests meaning the only way to really use stops effectively is in backtestRegular - i.e. rotational systems with stops, targets or both cannot use backtestRotational mode?

13

This is a deliberate dublicate of apply-stop-in-rotational-backtest.

Creating duplicates is against forum rules.

1 Like