# SanzP joins Logical-Invest

I joined the team at Logical-Invest.

Together with Frank, Alex and Scott (our info) we hope to create a place where we can develop strategies and actually offer them to the public for a low subscription.

This is something new. At least I think so.

If you have followed my blog you may have guessed that I support empowering the private investor to take investing into their own hands and use tools as good or better than the ‘big guys’ use. But I also understand that not everyone can become a full-time trader, learn programming or research the market for hours on end. Luckily there are quite a few management firms that are intelligent, publish their research, have good track records and are fairly priced.

We are taking a different route.

# Little “SanzP”

I have been absent from blogging for some time.
I have been giving most of my time to our little man.
He ‘s now 10 months old and just had his first swim!
So maybe Dad can go back to crunching those numbers…

# From Regime Switching to Fuzzy Logic -SP500

In the previous post I showed how one can implement “regime” switching to create a strategy that switches between a mean-reverting and a momentum sub-strategy.

Can we do something similar (or better) using Fuzzy Logic?

Here’s the setup: (here for some Fuzzy Logic backround)

We create a basic membership function for the RSI(2) indicator: “Low”, Medium” and “High”
We create a basic membership functions for the Correlation* indicator: “Low”,”High”.

We implement these rules:
1.//mean revert – LOW Autoccorelation
IF “rsi” is  “Low” AND “autocorrel” is “Low”, “Action”, 1 ; //Buy
IF “rsi” is “High” AND  “autocorrel” is “Low”, “Action”, -1 ; //Sell

//MOM – HIGH Autocorrelation
IF “rsi” is “Low” AND “autocorrel” is “High”, “Action”, -1 ; //Sell
IF “rsi” is “High” AND “autocorrel” is “High”, “Action”, 1 ;  //Buy

Here’s the Equity:

Conclusion:
As with Regime switching we can use Fuzzy Logic to solve the problem of using one strategy for trading pre- and post-2000 SP500. Furthermore, we have more robust and less specific rules to deal with (buy on “Low” RSI rather than Buy=RSI2<30).

—————
*By “Correlation Indicator” I am referring to the  22-day Correlation (see previous post) between the current return and the previous day’s return. In Amibroker Code:
Dayreturn=ROC(C,1);
AutoCor=Correlation(Dayreturn,Ref(Dayreturn,-1),22);

# Simple Regime Switching for SP500

 image from  http://brucekrasting.com/

Let us consider two possible ways to trade the SP500.

1. If the index falls today, we buy tomorrow at the open. This is a “mean-reversion” strategy.
2. If the index rises today, we buy tomorrow at the open. A “follow-through” strategy.

From the graphs below, we can see that neither of these strategies worked well from 1960 to today.

Mean Reversion Trading On SP500
Follow-Thru (momentum) trading on SP500

Let’s introduce a qualifier that will tell us which strategy to trade at what time.

We will try the most basic one: The correlation between today’s return (close to yesterday’s close) to the previous day’s return. If it is negative we ‘ll use a contrarian logic. If the correlation is positive we ‘ll use a momentum logic.

The indicator of choice is the 2-period Relative Strength Index (RSI).

So if correlation between yesterday’s and today’s return is less than zero we buy on a correction. Otherwise we buy on strength. We trade at the next Open.

Here’s the Amibroker Code:
<!–more–>
Dayreturn=ROC(C,1);
AutoCor=Correlation(Dayreturn,Ref(Dayreturn,-1),22);
SellContr=RSI(2)>70;
SellMoM=RSI(2)<50;
Sell=IIf(AutoCor<0,sellContr,sellMom);
qty=1;
PositionSize=-100/qty;
SetOption(“MaxOpenPositions”,qty);

# Strategies on The Cloud: TAA on Google Docs

Did you want to have a strategy on the cloud that monitors the market and updates you on new Buy/Sell signals (as well as number of shares, etc)  by email. Did you want to run it on best of breed “always ON” servers with free and accurate data?
How much would that set you back?Well, Nada! Courtesy of Google.This post will guide you through coding a simple Tactical Asset Allocation on Google’s Docs.
You need:
1. A Google account.
2. Google Docs.The system is similar to Faber’s TAA model using 5 Etfs.: SPY,TLT,VNQ,EEM,DBC
We buy or sell at the beginning of the month ONLY.
If Close > 200-moving Average then we buy the ETF.
If Close < 200-moving Average then we sell the ETF.

Pseudo Code:
If TodayIsNewMonth AND CloseETF>MA(200) Then Buy
If TodayIsNewMonth AND CloseETF<MA(200) Then Sell

Let’s get started. Go to Google Docs and create a new SpreadSheet. Call it TAA_5.
Once the spreadsheet is open in your browser, go up to the menu and select Tools–>Script Editor…
This should open a new script Editor. Select “SpreadSheet” as your project.

Lets start coding.
Google Docs scripting uses a version of JavaScript which seems fairly easy for non programmers.