Trying to understand backtest CAR and exposure statistics

I am trying to understand the CAR statistic and the exposure value from a backtest. Can anyone help clarify this for me? First the exposure question and then the CAR question.

FYI the trades are made annually but the test periodicity is Daily.
Here are the test results

Annotation 2020-09-06 101258

  1. The exposure shows 89.98% not 100% as I naively expected. Is this because the positions equity varies through the year and so deviates from the amount invested? The docs say that it is calculate per bar and as mentioned above the trades are made annually but the periodicity is Daily.

  2. The CAR shows to be 5.41% but when I use the formula mentioned in the docs I get 6.03%. I even wrote it in AFL so I could double-check my work. Can you help me understand what I am missing?

Annotation 2020-09-06 102207


@JM2138 your cagr formula has the wrong inputs. You were invested for 10 years not 9 years. The 10 year cagr is 5.41%, AmiBroker is correct, you are not. You may want to try a simple Excel code for comparison.


With regards to other mistakes you may be making, it is impossible to tell without seeing your code. It was your code/calculations that revealed your other error.


Thanks so much. I was so fixated on the trades that I overlooked that the actual range started a year earlier than the first trade. That also explains the exposure question.

I really appreciate the second set of eyes!

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