Category Archives: Must Know

EasyLanguage Code for Optimal F (Multi-Charts and VBA too!)

Optimal F in EasyLanguage for TradeStation and MultiCharts

Here is the code for the Optimal F calculation.  For a really good explanation of Optimal F I refer you to Ralph Vince’s Book Portfolio Management FORMULAS.  We had programmed this years ago for our Excalibur software and I was surprised the EasyLanguage code was really all that accessible on the internet.  Finding the optimal f is found through an iterative process or in programmers terms a loop.  The code is really quite simple and I put it into a Function.  I decided to create this function because I wanted to demonstrate the ideas from my last post on how a function can store variable and array data.  Plus this code should be readily available somewhere out there.

//OptimalFGeo by George Pruitt
//My interpretation Sept. 2018

input: minNumTrades(numericSimple);
vars: totalTradesCount(0),tradeCnt(0);
array: tradesArray[500](0);

vars: iCnt(00),jCnt(00),grandTot(0),highI(0);
vars: optF(0.0),gMean(0.0),fVal(0.0),HPR(0.0),TWR(0.0),hiTWR(0.0);
vars: biggestLoser(0.0),gat(0.0);

totalTradesCount = totalTrades;
If totalTradesCount > totalTradesCount[1] then
	tradeCnt = tradeCnt + 1; 
	tradesArray[tradeCnt] = positionProfit(1);

// Taken from my Fortran library - GPP and Vince Book PMF

optF = 0.0;
gMean = 1.00;
gat   = 0.00;
//Only calculate if new trade
IF(tradeCnt>minNumTrades and totalTradesCount > totalTradesCount[1]) then 
	biggestLoser = 0;
	grandTot = 0;
	For iCnt = 1 to tradeCnt //get the biggest loser
   		grandTot = grandTot + tradesArray[iCnt];
   		IF(tradesArray[iCnt]<biggestLoser) then biggestLoser = tradesArray[iCnt];
//	print(grandTot," ",biggestLoser);
	IF({grandTot > 0 and} biggestLoser <0) then 
//		print("Inside TWR Calculations");
		highI = 0;
		hiTWR = 0.0;
		for iCnt = 1 to 100
			fVal = .01 * iCnt;
			TWR = 1.0;
			for jCnt = 1 to tradeCnt // calculate the Terminal Wealth Relative
    			HPR = 1. + (fVal * (-1*tradesArray[jCnt]) / biggestLoser);
    			TWR = TWR * HPR;
 //   			print(fVal," ",iCnt," " ,jCnt," Trades ",tradesArray[jCnt]," HPR ",HPR:6:4," TWR : ",TWR:6:4," hiTWR",hiTWR:6:4," bl ",biggestLoser);
//			print(iCnt," ",TWR," ",hiTWR);
    			hiTWR = TWR;
    			optF = fVal;    	// assign optF to fVal in case its the correct one		
    			break;                     //highest f found - stop looping
		If (TWR <= hiTWR or optF >= 0.999999) then
			TWR  = hiTWR;
			OptimalFGeo = optF;  //assign optF to the name of the function
		gmean = power(TWR,(1.0 / tradeCnt));
		if(optF<>0) then GAT   = (gMean - 1.0) * (biggestLoser / -(optF));		
		print(d," gmean ",gmean:6:4," ",GAT:6:4);  // I calculate the GMEAN and GeoAvgTrade
Optimal F Calculation by Ralph Vince code by George Pruitt

VBA version of Optimal F

For those of you who have a list of trades and want to see how this works in Excel here is the VBA code:

Sub OptimalF()

    Dim tradesArray(1000) As Double
    i = 0
    biggestLoser = 0#
    Do While (Cells(3 + i, 1) <> "")
        tradesArray(i) = Cells(3 + i, 1)
        If tradesArray(i) < bigLoser Then biggestLoser = tradesArray(i)
        i = i + 1
    tradeCnt = i - 1
    highI = 0
    hiTWR = 0#
    rc = 3
    For fVal = 0.01 To 1 Step 0.01
        TWR = 1#
        For jCnt = 0 To tradeCnt
            HPR = 1# + (fVal * (-1 * tradesArray(jCnt)) / biggestLoser)
            TWR = TWR * HPR
            Cells(rc, 5) = jCnt
            Cells(rc, 6) = tradesArray(jCnt)
            Cells(rc, 7) = HPR
            Cells(rc, 8) = TWR
            rc = rc + 1
        Next jCnt
        Cells(rc, 9) = fVal
        Cells(rc, 10) = TWR
        rc = rc + 1

        If (TWR > hiTWR) Then
            hiTWR = TWR
            optF = fVal
            Exit For
        End If

    Next fVal
    If (TWR <= hiTWR Or optF >= 0.999999) Then
        TWR = hiTWR
        OptimalFGeo = optF
    End If
    Cells(rc, 8) = "Opt f"
    Cells(rc, 9) = optF
    rc = rc + 1
    gMean = TWR ^ (1# / (tradeCnt + 1))
    If (optF <> 0) Then GAT = (gMean - 1#) * (biggestLoser / -(optF))
    Cells(rc, 8) = "Geo Mean"
    Cells(rc, 9) = gMean
    rc = rc + 1
    Cells(rc, 8) = "Geo Avg Trade"
    Cells(rc, 9) = GAT

End Sub
VBA code for Optimal F

I will attach the eld and .xlsm file a little later.




Function Variable Data Survives Between Calls

Function Variable Data Survives from One Call to the Next – A Pretty Nifty Tool in EasyLanguage!

Creating a function that can store data and then have that data survive on successive function calls without having to pass information back and forth is really a cool and powerful tool in EasyLanguage.  In most programming languages, the variables defined in a function are local to that particular bit of code and once program execution exits the function, then the data is destroyed.  There are two exceptions (in other languages) that come to mind – if the variable is passed back and forth via their addresses, then the data can be maintained or if the variable is global in scope to the function and the calling program.  EasyLanguage prevents you from having to do this and this can definitely save on headaches.  I wrote a function that defines an array that will hold a list of trades.  Once the number of trades reaches a certain level, I then calculate a moving average of the last 10 trades.  The average is then passed back to the calling strategy.  Here is the simple code to the function.


{Function Name:   StoreTradesFunc by George Pruitt}
{Function to Calculate the average trade for past N trades.
 Function remembers the current trade count in tradeCnt.
 It also remembers the values in the array tradesArray.
 It does this between function calls. 
 Values - simple and array - undoubtedly are global to the function}
input: avgTradeCalcLen(numericSimple);
vars: totalTradesCount(0),tradeCnt(0);
array: tradesArray[500](0);

totalTradesCount = totalTrades;
If totalTradesCount > totalTradesCount[1] then
	tradeCnt = tradeCnt + 1;
	tradesArray[tradeCnt] = positionProfit(1);
//	print("Storing data ",tradesArray[tradeCnt]," ",tradeCnt);

If totalTrades > avgTradeCalcLen then
	Value2 = 0;
	For value1 = totalTrades downTo totalTrades - avgTradeCalcLen
		Value2 = value2 + tradesArray[value1];
	print("Sum of last 10 Trades: ",value2);
	StoreTradesFunc = value2/avgTradeCalcLen;
Store A List of Trades in a Function

I call this function on every bar (daily would be best but you could do it on intra-day basis) and it polls the function/keyword totalTrades to see if a new trade has occurred.  If one has, then the variable tradeCnt is incremented and the trade result is inserted into the tradesArray array by using the tradeCnt as the array index.  When you come back into the function from the next bar of data tradeCnt and tradesArray are still there for you and most importantly still intactIn other words there values are held static until you change them and remembered.  This really comes in handy when you want to store all the trades in an array and then do some type of calculation on the trades and then have that information readily available for use in the strategy.  My example just provides the average trade for the past ten trades.  But you could do some really exotic things like Optimal F.  The thing to remember is once you define a variable or an array in a function and start dumping stuff in them, the stuff will be remembered throughout the life of the simulation.  The function data and variables are encapsulated to just the function scope – meaning I can’t access tradesArray outside of the function.  One last note – notice how I was able to determine a new trade had occurred.  I assigned the result of totalTrades to my own variable totalTradesCount and then compared the value to the prior bar’s value.  If the values were different than I knew a new trade had just completed.

Anatomy Of Mean Reversion in EasyLanguage

Look at this equity curve:

As long as you are in a bull market buying dips can be very consistent and profitable.  But you want to use some type of entry signal and trade management other than just buying a dip and selling a rally.  Here is the anatomy of a mean reversion trading algorithm that might introduce some code that you aren’t familiar.  Scroll through the code and I will  summarize below.

inputs: mavlen(200),rsiLen(2),rsiBuyVal(20),rsiSellVal(80),holdPeriod(5),stopLoss$(4500);
vars: iCnt(0),dontCatchFallingKnife(false),meanRevBuy(false),meanRevSell(false),consecUpClose(2),consecDnClose(2);

Condition1 = c > average(c,mavLen);

Condition2 = rsi(c,rsiLen) < rsiBuyVal;
Condition3 = rsi(c,rsiLen) > rsiSellVal;

Value1 = 0;
Value2 = 0;

For iCnt = 0 to consecUpClose - 1 
	value1 = value1 + iff(c[iCnt] > c[iCnt+1],1,0);

For iCnt = 0 to consecDnClose - 1 
	Value2 = value2 + iff(c[iCnt] < c[iCnt+1],1,0);

dontCatchFallingKnife = absValue(C - c[1]) < avgTrueRange(10)*2.0;

meanRevBuy = condition1 and condition2 and dontCatchFallingKnife;
meanRevSell =  not(condition1) and condition3 and dontCatchFallingKnife;

If meanRevBuy then buy this bar on close;
If marketPosition = 1 and condition1 and value1 >= consecUpClose then sell("ConsecUpCls") this bar on close;

If meanRevSell then sellShort this bar on close;
If marketPosition = -1 and not(condition1) and value2 >= consecDnClose then buyToCover this bar close;


If barsSinceEntry = holdPeriod then
	if marketPosition = 1 and not(meanRevBuy) then sell this bar on close;
	if marketPosition =-1 and not(meanRevSell) then buytocover this bar on close;
Mean Reversion System

I am using a very short term RSI indicator, a la Connors, to initiate long trades.  Basically when the 2 period RSI dips below 30 and the close is above the 200-day moving average I will buy only if I am not buying “a falling knife.”  In February several Mean Reversion algos kept buying as the market fell and eventually got stopped out with large losses.  Had they held on they probably would have been OK.  Here I don’t buy if the absolute price difference between today’s close and yesterday’s is greater than 2 X the ten day average true range.  Stay away from too much “VOL.”

Once a trade is put on I use the following logic to keep track of consecutive closing relationships:

For iCnt = 0 to consecUpClose - 1 
	value1 = value1 + iff(c[iCnt] > c[iCnt+1],1,0);
Using the IFF function in EasyLanguage

Here I am using the IFF function to compare today’s close with the prior day’s.  iCnt is a loop counter that goes from 0 to 1. IFF checks the comparison and if it’s true it returns the first value after the comparison and if false it returns the last value.  Here if I have two consecutive up closes value1 accumulates to 2.  If I am long and I have two up closes I get out.  With this template you can easily change this by modifying the input:  consecUpClose.  Trade management also includes a protective stop and a time based exit.  If six days transpire without two up closes then the system gets out – if the market can’t muster two positive closes, then its probably not going to go anywhere.  The thing with mean reversion, more so with other types of systems, is the use or non use of a protective stop.  Wide stops are really best, because you are betting on the market to revert.  Look at the discrepancy of results using different stop levels on this system:

Here an $1,800 stop only cut the max draw down by $1,575.  But it came at a cost of $17K in profit.  Stops, in the case of Mean Reversion, are really used for the comfort of the trader.

This code has the major components necessary to create a complete trading system.  Play around with the code and see if you can come up with a better entry mechanism.

Making Trading Decisions on Current Month’s Profit/Loss

Keeping track of intra-month profit or loss

In real time trading I have noticed that once you reach a certain loss for the month its best, sometimes, to circle the wagons and quit trading until the beginning of the next month.  This concept works best for very short term or day trade algorithms, as its very easy to get started back up.  You can do this with Trend Following, but you must build a logical and replicable process for re-entering existing positions.  Let’s assume a trading algorithm whose averaging losing month is $1500 and you are currently down $2000 – what are the chances that you will revert to the mean or draw down further?  Probably 50/50.  Who knows you might turn around and actually make money by month’s end.  If you review a track record of a hedge fund manager, trader, or algorithm and they show a bar chart of monthly returns and there sticking out like a sore thumb is a big down bar, that kind of makes you think that could happen again.  If you can control the monthly downside without sacrificing the existing Profit:DrawDown ratio, then why not do it.

Sample Code To Monitor IntraMonth $P/L

if month(date) <> month(date[1]) then
	begMonthProf = netProfit; 
	print(d," ",t," ",begMonthProf);
	canTrade = true;
Capture Beginning Of Month Net Profit

Here I am comparing the month of the current bar against the month of the prior bar.  If they are not equal, then we have a new month.  Store the netProfit in the variable begMonthProf.  All you have to do is compare the current bar’s netProfit to begMonthProf and make a decision.  Here is some code:

Making a Trading Decision Based on Monthly $P/L

		If dayOfMonth(date) > 15 and begMonthProf - netProfit >= intraMonthMaxLoss then canTrade = false;
If Down MaxLoss for Month and Past Mid-Month - Quit Trading

If the day of the month is greater than 15 (month half over) and the difference between the current netProfit and begMonthProfit is greater than a negative intraMonthMaxLoss then quit trading for the month.  Only turn it back on the first bar of the next month.  See how this works for your algos.

How to Keep Track of BuysToday and SellsToday

The Useful MP

We all know how to use the reserved word/function MarketPosition – right?  Brief summary if not – use MarketPosition to see what your current position is: -1 for short, +1 for long and 0 for flat.  MarketPosition acts like a function because you can index it to see what you position was prior to the current position – all you need to do is pass a parameter for the number of positions ago.  If you pass it a one (MarketPosition(1)) then it will return the your prior position.  If you define a variable such as MP you can store each bars MarketPosition and this can come in handy.

mp = marketPosition;

If mp[1] <> 1 and mp = 1 then buysToday = buysToday + 1;
If mp[1] <> -1 and mp = -1 then sellsToday = sellsToday + 1;
Keeping Track of Buy and Sell Entries on Daily Basis

The code compares prior bar’s MP value with the current bar’s.   If there is a change in the value, then the current market position has changed.   Going from not 1 to 1 indicates a new long position.  Going from not -1 to -1 implies a new short.  If the criteria is met, then the buysToday or sellsToday counters are incremented.  If you want to keep the number of buys or sells to a certain level, let’s say once or twice,  you can incorporate this into your code.

If  time >= startTradeTime and t < endTradeTime and 
	buysToday < 1 and 
	rsi(c,rsiLen) crosses above rsiBuyVal then buy this bar on close;
If  time >= startTradeTime and t < endTradeTime and 
	sellsToday < 1 and 
	rsi(c,rsiLen) crosses below rsiShortVal then sellShort this bar on close;
Using MP to Keep Track of BuysToday and SellsToday

This logic will work most of the time, but it depends on the robustness of the builtin MarketPosition function Look how this logic fails in the following chart:

I didn't want entries in the same direction per day!
I only wanted 1 short entry per day!

MarketPosition Failure

Failure in the sense that the algorithm shorted twice in the same day.  Notice on the first trade how the profit objective was hit on the very next bar.  The problem with MarketPosition is that it only updates at the end of the bar one bar after the entry.  So MarketPosition stays 0 during the duration of this trade.  If MarketPosition doesn’t change then my counter won’t work.  TradeStation should update MarketPosition at the end of the entry bar.  Alas it doesn’t work this way.  I figured a way around it though.  I will push the code out and explain it later in more detail.

Input: rsiLen(14),rsiBuyVal(30),rsiShortVal(70),profitObj$(250),protStop$(300),startTradeTime(940),endTradeTime(1430);

Vars: mp(0),buysToday(0),sellsToday(0),startOfDayNetProfit(0);

If d <> d[1] then
	buysToday = 0;
	sellsToday = 0;
	startOfDayNetProfit = netProfit;

{mp = marketPosition;

If mp[1] <> 1 and mp = 1 then buysToday = buysToday + 1;
If mp[1] <> -1 and mp = -1 then sellsToday = sellsToday + 1;}

If entriesToday(date) > buysToday + sellsToday then 
	If marketPosition = 1 then buysToday = buysToday + 1;
	If marketPosition =-1 then sellsToday = sellsToday + 1;
	If marketPosition = 0 then
		if netProfit > startOfDayNetProfit then
			if exitPrice(1) > entryPrice(1) then buysToday = buysToday + 1;
			If exitPrice(1) < entryPrice(1) then sellsToday = sellsToday + 1;
		if netProfit < startOfDayNetProfit then
			if exitPrice(1) < entryPrice(1) then buysToday = buysToday + 1;
			If exitPrice(1) > entryPrice(1) then sellsToday = sellsToday + 1;
	print(d," ",t," ",buysToday," ",sellsToday);

If  time >= startTradeTime and t < endTradeTime and 
	buysToday < 1 and 
	rsi(c,rsiLen) crosses above rsiBuyVal then buy this bar on close;
If  time >= startTradeTime and t < endTradeTime and 
	sellsToday < 1 and 
	rsi(c,rsiLen) crosses below rsiShortVal then sellShort this bar on close;


A Better Buy and Short Entries Counter

TradeStation does update EntriesToday at the end of the bar so you can use this keyword/function to help keep count of the different type of entries.  If MP is 0 and EntriesToday increments then you know an entry and an exit has occurred (takes care of the MarketPosition snafu) – all you need to do is determine if the entry was a buy or a sell.  NetProfit is also updated when a trade is closed.   I establish the StartOfDayNetProfit on the first bar of the day (line 9 in the code) and then examine EntriesToday and if NetProfit increased or decreased.  EntryPrice and ExitPrice are also updated at the end of the bar so I can also use them to extract the information I need.   Since MarketPosition is 0  I have to pass 1 to the EntryPrice and ExitPrice functions – prior position’s prices.  From there I can determine if a Long/Short entry occurred.  This seems like a lot of work for what you get out of it, but if you are controlling risk by limiting the number of trades (exposure) then an accurate count is so very important.

An alternative is to test on a higher resolution of data – say 1 minute bars.  In doing this you give a buffer to the MarketPosition function – more bars to catch up.


Pyramiding and then Scaling Out at Different Price Levels – EasyLanguage

TOTAL, TOTAL, TOTAL – an important keyword

I just learned something new!  I guess I never programmed a strategy that pyramided at different price levels and scaled out at different price levels.

Initially I thought no problem.  But I couldn’t get it to work – I tried everything and then I came across the keyword Total and then I remembered.  If you don’t specify Total in you exit directives then the entire position is liquidated.  Unless you are putting all your positions on at one time – like I did in my last post.   So remember if you are scaling out of a pyramid position use Total in your logic.

vars: maxPosSize(2);

If currentContracts < maxPosSize - 1 and c > average(c,50) and c = lowest(c,3) then buy("L3Close") 1 contract this bar on close;
If currentContracts < maxPosSize and c > average(c,50) and c = lowest(c,4) then buy("L4Close") 1 contract this bar on close;

If currentContracts = 2 and c = highest(c,5) then sell 1 contract total this bar on close;
If currentContracts = 1 and c = highest(c,10) then sell 1 contract total this bar on close;
Scaling Out Of Pyramid

Why you have to use the Total I don’t know.  You specify the number of contracts in the directive and that is sufficient if you aren’t pyramiding.  The pyramiding throws a “monkey wrench” in to the works.