ThinkScript - MM-PS Code/Logic Question...

October 21st, 2015, 11:38 PM

Despite working with thinkorswim for over 10 years now, I am obviously still a novice thinkScripter when it comes to crafting custom solutions. With that said, I've been trying to write my own "study", really it's more of a "dashboard" of sorts, to address my need to keep Money Management and Position Sizing front and center when considering a trade...

Code

declare lower;

input priceLo = low;
input priceHi = high;
input price = close;
input length = 10;
input averageType = AverageType.WILDERS;
input multiplier = 2.0;
input accountSize = 100000;
input accountRiskTolerance = 0.015;

def ATR = MovingAverage(averageType, TrueRange(high, close, low), length);
def ATRmultiple = multiplier * ATR;
#def avgPercentMove = (ATR / price) * 100;
def longStopLoss = priceLo - ATRmultiple;
def shortBuyCover = priceHi + ATRmultiple;
def tradeRisk = accountSize * accountRiskTolerance;
def sharesBuyBorrow = tradeRisk / ATRmultiple;
def tradeSizer = (tradeRisk / ATRmultiple) * price; 

AddLabel(yes, "Current Volatility: " + Round(ATR, 2), CreateColor (255, 255, 255));
#AddLabel(yes, "Average Move: " + Round(avgPercentMove, 2) + "%", CreateColor (255, 255, 255));
AddLabel(yes, "Total Per Trade Risk Limit : " + "$ " + Round(tradeRisk, 2), CreateColor (255, 255, 255));
AddLabel(yes, "Shares to Buy or Borrow: " + Round(sharesBuyBorrow, 0), CreateColor (255, 255, 255));
AddLabel(yes, "Trade Size: " + "$ " + Round(tradeSizer, 2), CreateColor (255, 255, 255));
AddLabel(yes, "If Going LONG -> Place Stop at " + Round(longStopLoss, 2), CreateColor (255, 255, 255));
AddLabel(yes, "If Going SHORT -> Place Cover at " + Round(shortBuyCover, 2), CreateColor (255, 255, 255));

While the code basically does provide some helpful information, there are a few inconsistencies:
1. Admittedly, this code employs both the Fixed Fraction and ATR Volatility position sizing strategies...I would prefer to follow the ATR strategy only if possible...
2. Somehow the calculation for "tradeSizer" on occasion exceeds "accountSize"...

Any feedback, thoughts or suggestions to improve this code would be greatly appreciated...

Thanks in advance...

October 29th, 2015, 10:26 AM

While I am still trying to sort out the code in terms of Fixed Fraction vs. ATR Volatility, I thought I would post the solution I came up with to resolve the "tradeSizer" exceeding "accountSize" issue in the hopes it might prove useful/helpful to someone else somewhere along the way...

Code

AddLabel(yes, if tradeSizer < accountSize then "Trade Size: " + "$ " + Round(tradeSizer, 2) else "Trade Size: Exceeds available funds", CreateColor (255, 255, 255));

ThinkScript - MM-PS Code/Logic Question...

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ThinkScript - MM-PS Code/Logic Question...