Slashdot Mirror
Stock-Picking Computers
eldavojohn writes "A while ago, Slashdot ran an article on Algorithms used to augment or replace analysts. Today, the NY Times is running an article on stock-picking computers with quotes from the lovable Ray Kurzweil." From the article: "'Investment firms fall over themselves advertising their latest, most esoteric systems,' said Mr. Lo of M.I.T., who was asked by a $20 billion pension fund to design a neural network. He declined after discovering the investors had no real idea how such networks work. 'There are some pretty substantial misconceptions about what these things can and cannot do,' he said. 'As with any black box, if you don't know why it works, you won't realize when it's stopped working. Even a broken watch is right twice a day.'"
While the idea of stock picking algorithms is neat; market history suggest it won't work a a way to predict performance. What would be interesting is to better search for arbitrage opportunities to exploit faster than others. Of course, eventually others do the same and it becomes an arms race.
I'm a consultant - I convert gibberish into cash-flow.
If you have a giant set of data, and you set a computer on it for long enough, it should be able to come up with some rather solid paterns/corelations/etc. You come up with these things, and if you don't have to wory about paying the stock broker what ever cut for each transaction (because you are the broker), then constantly trading on these thigns seems like agreat idea.
However, it still can't predict things that a human can (yet). I doubt that a computer can incorporate thigns like global news, company announcements, and other such real world variables into how it makes judgments. That was the one thing that the article didn't really talk about.
So I doubt we will see these "black boxes" replacing brokers, simply suplimenting them.
Do Or Do Not, There Is No Spoon, There Is Only Zuul. Everything in the above post is probably opinion.
First you have to get a license for the exotic pet, then you have to import it, then you have get it vaccinated and take out liability insurance in case it throws feces at a passing dignitary.
No, no, no, there's a better way. Get me a case of beer and a copy of the WSJ and a dartboard. I'm at least as random as a monkey after 24 beers.
The only surefire protection against Microsoft infections is abstinence. - The Onion
There are so many theoretical problems with automated stock picking systems that I could spend all day working on this post. Instead, I'll ignore all but two.
First, no matter how well you can predict based on patterns, when you are picking individual stocks, there is such a huge influence from the chaos of human nature that, from day to day, no matter how appropriate your predictions are (based on history), they may have nothing at all to do with reality.
Additionally, if you get enough of these stock picking systems in operation, they can actually change the dynamics of the market, keeping them from being accurate for years as they all try to account for the activities associated with each others' predictions.
The problem with stocks is that in order to know how they are going to perform, you have to know not only what the company is going to do and how their customers are going to respond, but also how the investing public is going to take that news. It's an odd mix of fundementals and faith, in my experience.
The CB App. What's your 20?
That's not the same as automated stock picking.
Automated trading systems 'generally' are used to take a position in a stock that has already been picked.
So, trader A in Goldman Suchs wants to take a long position (buy) 100K shares of IBM, so he assigns that trade to the algorithmic trading engine, which might offer him various algorithms to help fulfill his position at the best possible price, ranging from %vol, VWAP, 'iceberg' or other type of algorithm.
notice, though, that the trader already had the stock to trade chosen, he didn't let the algorithmic engine choose it for him.
[ Yes, I am joking. I'm quite sure Mr. Lo is brilliant -- just maybe a touch too honest. :-) ]
John
In some cases, the result seems to work more consistently.
I had a friend who worked in the AI department of Lockheed (about 20 years ago) and they developed the software that was used for the Robert Prector's Elliot Wave newsletter. Every two years they would give the program to a couple of people to try for 6 months. These people would invest $10,000, use the program and follow the guidelines, then evaluate the results. I was privy to the outcomes of three of these tests in the mid-nineties, and the lowest was earned $15,000 and the highest was earned $36,000. These are pretty good results. (However, the stock market was steadily climbing during those years and I wasn't able to compare results with EWT competition. Still, if I was able to consistently get 30%/year on my investments...)
Back in the 70's, Dean Witter had a program called PACE. I know two people who had a system for using it that earned them over $100,000/year, and they never deviated from the program while I knew them.
Then I have a friend who is a very conservative money manager (manages a couple hundred million of other people's money), and over the period that stocks crashed (remember Enron and Worldcomm?) he only had two clients lose any money, and the biggest loss was less than %15. He claims that these programs are mostly bunk. (This guy is a perfectionist, and I bet a computer is no more disciplined than he is.)
These programs are not investment management programs. The principles of investment management are pretty simple. The best book I know on the subject is still Benjamin Graham and David Dodd's book, "Security Analysis". However, the problem is finding opportunities that comply with the principles. Systematic data analysis by computer could have a profound effect, and that's what most of these programs do.
BTW, the article mentions that profits are slowing down: In Robert Prector's book, "The Elliott Wave Theory" and in his newsletter, he sort of predicts that as information becomes more available for analysis trading will be done more rapidly on spreads that may show profits as low as 1.5%
"The mind works quicker than you think!"
Found it: it was Nova: "Trillion Dollar Bet". Here's the transcript.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Personally, I'd be more worried about it throwing the darts at a passing dignitary, or at myself.
Remember: sticks and stones may break your bones but feces just splatters.
When the posters fear their moderators, there is tyranny; when the moderators fears the posters, there is liberty.
This is one of the most beloved urban legends of people who need an excuse for their poor luck.
r l2html-21923http://www.webtrading.com/issue18.htm> ). This does not mean the experts are all that great - the score is 26 to 25 againsT the Dow Jones Industrial Average.
0 7665534-search.html?KEYWORDS=dart+picks&COLLECTION =wsjie/6monthrel=url2html-21923http://online.wsj.c om/article/SB115845214007665534-search.html?KEYWOR DS=dart+picks&COLLECTION=wsjie/6month>).
In fact, in the Wall St. Journal's long-running contest, the experts have out-performed the darts 29 to 21 times (ahref=http://www.webtrading.com/issue18.htmrel=u
However, in the less-long-running contest of Wall St. Journal readers versus darts, the readers are getting trounced 13 to 9 (ahref=http://online.wsj.com/article/SB1158452140
What is true, and more damning to investment professionals, is our poor performance versus broad-based indexes, which are inexpensive investments.
>We will say nothing, or we will try to mislead you.
So in this light, how am I suppose to interpret the rest of your post?
The surprise isn't how often we make bad choices; the surprise is how seldom they defeat us.
A HUGE amount of the market is in retirement funds or investment funds designed to be liquidated through retirement. My generation will be retiring soon, and withdrawing their funds from the market. If the USA keeps producing, it may be a good place for foreign investment that will buy the stocks being sold. However, there's about 10 Trillion dollars of off-balance-sheet liabilities in Social Security, Medicaid and Medicare out there. (If the USA was Enron or Worldcomm, the last 8 Presidents and all the legislators would be in prison today.) I suspect that the government will fund these liabilities by inflating the currency and raising taxes, making the USA attractive investment opportunity for only China. The gambling schemes, including the derivatives you talk about, will fold. The world will get hungry...invest in food.
I support the investor's right to be as stupid as they wish. A buy and hold regulation won't do as much good as something like the Fair Tax Plan, increased personal debt reduction, a balanced budget, and reduced spending. Presumably, investments are property that an investor should be able to divest anytime. Leave the government out of it.
"The mind works quicker than you think!"
First of all, the article summary seems a bit misleading because people might think we're talking about "stock picking" as in analyst opinions/monkeys picking stocks. That's not so, this is about software driven trading. Often this is of a very short term nature, so in a way the growing use of program trading is the "new day trading" fad.
In the industry it's called "program trading" and refers to automated, algorithmic trading of instruments such as stocks, futures, forex. This is regularly done by many banks and large funds, and also small investors. In fact there is a discount brokerage which I'll just call IB here, that has an API which lets anyone program their own computerized trading. It's a bit "too easy" to do.
That doesn't mean it's always profitable in the long term, but without a doubt people are profiting at least in the short term. The software has multiple strategies, well documented approaches and algorithms. Generally the trading robot is trying to ride trends.
As someone who follows these things, here are a few criticisms I'm aware of:
1. These short term trading activities require high leverage, because trades have to be for large amounts of money to make them worthwhile. You need large amounts of money to make this work, because things like trading costs eat into profits tremendously. Again, like day trading.
2. High leverage is risky because one big mistake or unpleasant event could wipe out tons of past small gains. Risk management becomes a key issue. Some would argue that perceived risk in markets these days is unreasonably low. Does this unbalance the risk/reward equation?
3. Market-wide, we know program trading has increased dramatically on US exchanges. Add to this the undocumented program trading (smaller traders who don't have to report it to anyone) and basically there are a ton of computer algorithms out there today trading stocks. Everybody can't make money at the same time, so to profit the participants have to use even greater leverage = more risk.
4. Programming flaws, bugs, or improper risk management could have tremendous market-wide implications. Take for example the huge market moves in 1987; the drop was a "20-sigma" event and not anywhere within the realm of possibility back then. Obviously the models failed to handle it. Similarly, the next time we have a "big event" in markets, today's algorithms might fail. If a large number of computers choke while trading, could bad things happen?
5. So under unstable market conditions, the program trading could lead to increased volatility (like daytrading caused volatile markets during the crash). But under stable market conditions, like we have today, program trading seems to smooth out daily movements. Notice that the US markets hardly move as much as 1% in a day; trends are smooth and volatility is extremely low. The VIX, a volatility measure, has hit historic lows.