If I understand your question correctly, then I believe that it is the first bar of account equity (as found in the backtester object) to last bar of account equity, as shown in my earlier example.
Mike
--- In
amibroker@xxxxxxxxx ps.com, Keith McCombs <kmccombs@xx .> wrote:
>
> Mike and Steve --
> The limiting of range to that of the data available, rather than to
> settings in AA, is less than obvious from reading the User's Guide.
>
> When doing portfolio testing, is the range on equity by equity basis, or
> from the first bar of any equity to the last bar of any equity? (I
> can't even imagine how one would either calculate or interpret the
> results doing it equity by equity).
>
> BTW, I believe your answers highlight my request for "AFL
formulas to
> produce results equivalent to
> those shown in AB back tester analysis"
>
> I am familiar with Fred's IO portfolio.afl, and will indeed examine it
> more closely. Good suggestion.
>
> Thank you.
> -- Keith
>
> Mike wrote:
> >
> > Pretty much amounts to the same thing since there are generally 252
> > bars per 365 days. But, the earlier sample could easily be modified to
> > instead use:
> >
> > | first = LastValue(ValueWhen (Status(" firstb arinrange"),
> > DaysSince1900( )));
> > last = LastValue(ValueWhen (Status(" lastbarinrange" ),
> > DaysSince1900( )));
> > ...
> > CAR = 100 * ((bo.Equity/ bo.InitialEquity ) ^ (365/(last - first +
> > 1)) - 1);
> > < /font>|
> >
> > Mike
> >
> > --- In
amibroker@xxxxxxxxx ps.com, "Steve Dugas" <sjdugas@> wrote:
> > >
> > > Hi - For CAR, the user guide gives the formula used by AB...
> > >
> > > AmiBroker is one of the few programs that calculates annual returns
> > correctly and will give you correct value of 20% as shown in the
> > example above. The formula that AmiBroker uses for annual return
> > calculation is as follows:
> > >
> > > correctly_annualize d_perc_return = 100% * (
> > (final_value/ initial_value) ^ ( 365 / days_in_test ) - 1 )
> > >
> > > ----- Original Message -----
> > >
> > > From: Mike
> > > To:
amibroker@xxxxxxxxx ps.com> > > Sent: Tuesday, December 01, 2009 5:01 PM
> > > Subject: [amibroker] Re: What's a good k ratio,and thoughts on when
> > k ratio clashes with MDD and Shar
> > >
> > >
> > >
> > >
> > > Keith,
> > >
> > >
> > > Change the granularity of your formula to be on a bar basis, as
> > opposed to an annual basis, and you should come out with a value very
> > close to what AB produces.
> > >
> > >
> > > e.g.
> > >
> > >
> > > SetCustomBacktestPr oc("");
> > >
> > > if (Status("action" ) == actionPortfolio) {
> > > first = LastValue(ValueWhen (Status(" firstbarinrange" ), BarIndex())) ;
> > > last = LastValue(ValueWhen (Status(" lastbarinrange" ),
BarIndex())) ;
> > > bo = GetBacktesterObject ();
> > >
> > > bo.Backtest( );
> > >
> > > CAR = 100 * ((bo.Equity/ bo.InitialEquity ) ^ (252 / (last - first +
> > 1)) - 1);
> > >
> > > bo.AddCustomMetric( "MyCAR", CAR);
> > > }
> > >
> > >
> > > I believe that the information for K-Ratio is out of date. The
> > formula has been revised. I seem to recall the author suggesting that
> > a value of 0.5 was good. Howard has suggested that 0.15 was good.
> > >
> > >
> > > Note that the metrics you were comparing dealt with return without
> > regard for how that return was achieved. K-Ratio measures the
> > consistency of the return. So, it is not unusual to have strong
> > CAR/MDD with poor K-Ratio. A couple of big gains would improve
the
> > former while hurting the latter.
> > >
> > >
> > > I seem to recall a posting in this forum offering many of the
> > calculations that you're asking for. Otherwise, you can try looking at
> > the Portfolio.afl of IO since it displays many of the same values.
> > >
> > >
> > > Mike
> > >
> > > --- In
amibroker@xxxxxxxxx ps.com, Keith McCombs kmccombs@ wrote:
> > > >
> > > > Mike --
> > > > The tooltip (which I must admit I was unaware of), unfortunately,
> > > > provides no more information than the "AmiBroker User's Gu ide"
> > (which I
> > > > referred to in my previous posting).
> > > >
> > > >
Using your suggestion of Googling the metrics, I Googled CAR, and
> > came
> > > > up with the following link:
> > > >
> >
http://www.investor glossary. com/compound- annual-return. htm#rate_ definition> > > > resulting in the definition, "The formula for the compound annual
> > return
> > > > is ((Ending Value) /(Beginning Value))^(1/Number of years)-1."
> > > >
> > > > I just ran a portfolio backtest for a strategy from 10/26/07 to
> > > > 10/25/09, a period of 2years. The results were:
> > > > Initial capital 100000.00 100000.00 100000.00
> > > > Ending capital 134224.01 134224.01 100000.00
> > > > Net Profit 34224.01 34224.01 0.00
> > > > Net
Profit % 34.22 % 34.22 % 0.00 %
> > > > Exposure % 2.70 % 2.70 % 0.00 %
> > > > Net Risk Adjusted Return % 1268.77 % 1268.77 % N/A*> > Annual
> > Return % 19.79 % 19.79 % 0.00 %
> > > > Risk Adjusted Return % 733.63 % 733.63 % N/A
> > > >
> > > >
> > > > Note that the net profit over the two year period is 34.22% and the
> > > > Annual Return is shown as 19.79%. However if one calculates the
> > Annual
> > > > Return using net profit and the formula above,
> > > > 1.3422401^.5 -1 = 15.855%.
> > > >
> > > > The AB User's Guide suggests that a good system might have the
> > following
> > > > characteristics:
> > > > "CAR/MaxDD - Compound Annual % Return divided by Max. system %
> > drawdown.
> > > > Good
if bigger than 2".
> > > >
> > > > "Sharpe Ratio of trades - Measure of risk adjusted return of
> > investment.
> > > > Above 1.0 is good, more than 2.0 is very good."
> > > >
> > > > "K-Ratio - Detects inconsistency in returns. Should be 1.0 or more."
> > > >
> > > > The s trategy tested above showed the following:
> > > > MDD = -8.02%
> > > > CAR/MDD = 2.47
> > > > RRR = 4.32
> > > > Sharpe = 5.27
> > > > K-Ratio =0.0051 (seems rather inconsistent with others)
> > > >
> > > > I have back tested many profitable, low risk systems over the
> > years, and
> > > > do not recall ever seeing a K-Ratio greater than 1.0.
> > > >
> > > > So, I'd still like to have *AFL formulas to produce
results
> > equivalent to
> > > > those shown in AB back tester analysis*.
> > > >
> > > > And, BTW, does AB calculate MDD from High/Low bars or from equity
> > curve
> > > > based on closes. I suspect the latter, but don't really know.
> > > >
> > > > Thank you.
> > > > -- Keith
> > > >
> > > >
> > > > Mike wrote:
> > > > >
> > > > >
> > > > > For a textual description, generate a backtest report and the n
> > hover
> > > > > your mouse over any metric name. The tooltip will provide a
> > > > > description of the metric. For most, a mathematical explanation
> > can be
> > > > > found via google.
> > > > >
> > > > >
Mike
> > > > >
> > > > > --- In
amibroker@xxxxxxxxx ps.com > > <mailto:amibroker% 40yahoogroups. com>,
> > > > > "Potato Soup" potatosoupz@ wrote:
> > > > > >
> > > > > > Yes, I still don't have an explanation for what car is. And
> > all the
> > > > > others I listed.
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Keith McCombs kmccombs@
> > > > > > Date: Mon, 30 Nov 2009 14:05:23
> > > > > > To:
amibroker@xxxxxxxxx ps.com > > <mailto:amibroker%
40yahoogroups. com>>
> > > > > > Subject: Re: [amibroker] What's a good k ratio,
> > > > > > and thoughts on when k ratio clashes with MDD and Sharpe?
> > > > > >
> > > > > > One thing that I would find most helpful, as far as
> > performance metrics
> > > > > > are concerned, is a precise definition of each metric in
> > "AmiBroker
> > > > > > User's Guide" (page 156 for v5.20), including AFL formulas to
> > produce
> > > > > > results equivalent to those produced by AB back tester analysis.
> > > > > >
> > > > > > -- Keith
> > > > > >
> > > > > > Howard B wrote:
> > > > > > >
> > > > > > >
> > > > > > > Hi PS
--
> > > > > > >
> > > > > > > One way to get a feeling for values for metrics and objective
> > > > > > > functions is run an optimization, giving you a range of
> > results. If
> > > > > > > necessary, peek into the future so you are certain to get
> > some really
> > > > > > > good results.
> > > > > > >
> > > > > > > Look through the list of results, pick some individual
> > results with a
> > > > > > > variety of values for the metrics you want to learn about.
> > > > > > >
> > > > > > > Set the default value of the optimized variables to the specific
> > > > > > > values you chose.
> > > > > > >
> > > > > > >
Run a single backtest. Plot the equity curve.
> > > > > > >
> > > > > > > When you have done a few of these and have a feeling for the
> > > > > > > characteristics of the systems you would like to trade,
> > print out the
> > > > > > > plot of the equity curves and write the values of the
> > metrics and
> > > > > > > objective functions on the printout.
> > > > > > &g t;
> > > > > > > ------------ --------- --
> > > > > > >
> > > > > > > Your question about interpretation.
> > > > > > >
> > > > > > > My preference is for objective functions that reward equity
> > growth
> > > > > and
> > > > > > > penalize drawdown.
CAR/MDD, RAR/MDD, RRR, Recovery Factor,
> > K-Ratio,
> > > > > > > Ulcer Performance Index, and Sharpe Ratio all do that. In all of
> > > > > > > these cases, larger values are better.
> > > > > > >
> > > > > > > The important results are the out-of-sample results. We are
> > looking
> > > > > > > for logic and parameter values that not only perform well
> > in-sample,
> > > > > > > but that also perform well out-of-sample.
> > > > > > >
> > > > > > > When you run walk forward tests, you will find that s ome
> > objective
> > > > > > > functions give high rank to alternatives that do tend to
> > perform well
> > > > > > > out-of-sample, while other objective functions
select
> > alternatives
> > > > > > > that often do not perform well out-of-sample. You will need
> > to run
> > > > > > > some of your own tests to get a feeling for how these work
> > on your
> > > > > > > trading systems.
> > > > > > >
> > > > > > > My experience is that using net profit is usually a poor
> > objective
> > > > > > > function, although it is the default (and often the only)
> > selection
> > > > > > > for some trading systems development platforms other than
> > AmiBroker.
> > > > > > >
> > > > > > > Fund managers are evaluated on the Sharpe Ratio of their
> > performance.
> > > > > > > My experience is that systems selected using
Sharpe R atio
> > tend to
> > > > > > > perform poorly out-of-sample.
> > > > > > >
> > > > > > > Standard Error is a measurement of the smoothness of the
> > equity line
> > > > > > > -- smaller values are better. But optimizing to minimize
> > standard
> > > > > > > error alone may give high ranks to systems that have trading
> > > > > > > characteristics that you do not want. For example, if you
> > have the
> > > > > > > options set so that the equity earns interest when ever it
> > is not
> > > > > in a
> > > > > > > position, then using standard error will reward alternatives
> > that
> > > > > stay
> > > > > > > in cash and trade
infrequently.
> > > > > > >
> > > > > > > ------------ --------- ---
> > > > > > >
> > > > > > > One of the very valuable features of AmiBr oker is the
> > capability for
> > > > > > > the system developer to create whatever objective function
> > he or she
> > > > > > > wants to use. It does not have to be limited to those that are
> > > > > > > distributed with AmiBroker and appear in the list of
> > metrics. You
> > > > > > > might want to combine metrics -- for example to reward
> > alternatives
> > > > > > > whose trading frequency suits your preferences, while also
> > rewarding
> > > > > > > equity growth and penalizing drawdown.
> > > > > >
>
> > > > > > > Thanks,
> > > > > > > Howard
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > On Sat, Nov 28, 2009 at 11:33 PM, potatosoupz potatosoupz@
> > > > > > > <mailto:potatosoupz @> wrote:
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > I don't see any good definitions for the metrics below. I am
> > > > > > > familiar of course with Sharpe, and Ulcer Index. I'm finding
> > it a
> > > > > > > bit hard to reconcile the differences. How would you reconcile a
> > > > > > > backtest that has a max draw down % that is smaller than it's
> >
> > > > > profit %, a low ulcer index, a high Sharpe, but a very low k
> > ratio
> > > > > > > (< .05)?
> > > > > > >
> > > > > > > Ulcer Index in my mind is one of the best metrics outside of a
> > > > > > > much deeper quantitative treatment of things. Thoughts?
> > > > > > >
> > > > > > > CAR/MDD ?
> > > > > > > RAR/MDD ?
> > > > > > > Payoff Ratio ?
> > > > > > > Standard Error ?
> > & gt; > > > > RRR ?
> > > > > > > Recovery Factor ?
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > >
>
> > >
> > *
> > * *
> > * *
> > **
> > * *
>