This tumblr examines stock market trading models. It exists solely to satisfy my interests in investing, programming, and data analysis. The aim is to improve my knowledge in these areas through the investigation of models I find on Twitter, Tumblr, and anywhere else my browser lands.
Keep this in mind: Anyone can write a blog on Tumblr. I do not have any magic beans. Do your own verification. Statistical analysis requires tools and methods of which I am only vaguely familiar (not to mention unqualified to undertake).
Don’t trade based on anything you read here. And if you can’t follow that advice, be sure to only trade using a paper portfolio and not commit real monies. Conscientiously trading a paper portfolio for months before committing real money should be considered mandatory before trading based upon a model. Otherwise you are vulnerable to confirmation bias.
When I run across a model that piques my interest, I write code to implement the rules of the model (so far as I understand) and then attempt to quantify the performance of the model using data from sources like Yahoo Finance or the St. Louis Federal Reserve Bank FRED website.
My initial assumption is the model is wrong. My analysis attempts to quantify how and where the model is wrong.
In my experience, trading models usually fail in one of the following ways (additional bad outcomes omitted):
Cannot be verified (i.e., is no better than random)
Verifiable, but infeasible for real trading (i.e., trading costs and draw downs eventually absorb profits)
Fail in future (i.e., back testing bias / temporary correlations are in effect)
Other than long term dollar cost averaging in a 401(k)/IRA at a low cost mutual fund provider, such as Vanguard, I don’t know of a consistently profitable investment model.
I do believe there are profitable proprietary trading models. Hedge funds, high-frequency traders, and investment banks have advantages, such as market access and cost, which allow them to profitably trade using models.
So far as I am aware, these proprietary models are not published and the structural advantages which permit their profitability are not available to you dear reader.