Best Use of Lego Mindstorms…
…EVER!
While normal distributions are nice and wonderful, they aren’t really feasible in the world of finance. This is because the market can be so volatile and fickle that variances become meaningless.
So, enter fat-tailed distributions. These are distributions where events deviate significantly from the mean in comparison to normal distributions. What this means in terms of the stock market is that assets and investments are prone to jumps (in either directions).
On this topic, Paul Kedrosky links to an interesting presentation on Fat Tailed distributions by Northfield, the guys that make analytical and investment software.
It’s quite interesting and talks about some work that’s being done in this area.
On a related note, another area of application for Fat tailed distributions is the CRM arena. Contact-centers and self-service applications (i.e. IVRs) receive millions of calls a day, and there is just as much variation in C-sats, agent performance, AHT and so on.
It would be interesting to apply some of these tools and techniques to call-center analytics and see how well those work.
Sometimes, I just amaze myself — as a follow up to my previous blog post, my Dad just sent me this article that talks about how the RBI has eased the currency outflow norms to contain the rise of the Rupee against the US Dollar.
From the article –
In a bid to neutralise the impact of huge capital inflows and check the sustained rise in the rupee’s value against the dollar, the Reserve Bank of India (RBI) has further liberalised the foreign exchange norms to boost the outflow of funds from India. The RBI has now allowed resident Indians to transfer up to $2 lakh (around Rs 80 lakh) a year abroad without its approval under the Liberalised Remittance Scheme (LRS). The earlier limit was $1 lakh (Rs 40 lakh) a year. Now Indians can transfer $2 lakh to acquire and hold immovable property, make investments in financial instruments or purchase any other asset abroad without any prior approval.
Worried muchly about what FIIs might do, me hearties? And of course, there are those exporters who will be taking a hard hit otherwise, too.
I found this interesting article that talks about how hedge funds in India part-take in currency arbitrage. From the article –
Hedge funds – known for their high-risk, high-return short-term investment plays – are taking bets on the upward and downward movement of the rupee against the dollar under the pretext of investing in equities.
As one of my friends recently commented, this is probably a good time to invest in the USD, since it seems to be at an all-time low. While there are speculations that it may go still lower, you can always rely on the various national reserve banks to peg the dollar before it goes down too low.
Last June and early July, most analysts said the rupee could not continue appreciating and the RBI would intervene to ensure that the rupee corrects a bit. This view was shared by many foreign brokerage houses as well.
The RBI did intervene, but only to stop the rupee from appreciating further. The hedge funds also believed that the rupee would fall against the US dollar.
Of course it did. You know, it just might make everyone’s life easier if RBI allowed free dollar convertibility within India. When will these people learn?
No, really. The former chairman of the federal reserve meets our very own tongue-in-cheek comedian. Greenspan makes a rather a interesting comment:
“What a sound money system does is to stabilize all the elements in it and reduces the uncertainty that people confront.”
I really think he should meet this guy.
(Thanks to PD for the link.)
PD recently recommended two excellent books by Nassim Nicholas Taleb (homepage), the mathematician turned philosopher turned epistemologist. I am half way done with one of them, Fooled by Randomness and I have a brand new copy of The Black Swan sitting right here on my desk.
While I was reading the books, one thing that stuck me was this — within a given system, how many such quant funds (such as Taleb’s old firm, Empirica Capital LLC) does it take for Taleb’s risk-based hedge funds to succeed? Or inversely, how many is too many that would cause the system to fall down upon itself?
To find a way to answer these questions, I am interested in starting with finding out the possible success rates for these firms.
Let me explain myself. Let us assume that there are 100 quant firms that invest the way Taleb’s old firm did. This would mean that you have a hundred firms slowly bleeding to death, waiting for that one Black Swan, when things work out for them.

Now, for the sake of argument, let us assume that only half of these firms are going to succeed to some extent while the other half are going to fail.

The probability of all fifty of these firms having the exact same degree of success is quite low. In fact, it is more likely that within their given domain, these fifty firms have some sort of distribution of success-rates.
Let’s assume that two kinds of distributions are possible here — the first, obviously, is a Bell-curve, assuming a normal distribution. Going this route, we could try and apply the 68-95-99.7 rule and get the following distribution (courtesy Wikipedia):
So, let us assume that 68.2% of the quant firms are good enough for us to work with. This would leave us with:

This leaves us with about 34 firms which may perform well enough. Of course, the other interesting thing would be to see how much longer they can bleed themselves (assuming a decaying function) and seeing what percentage of these 34 companies actually “decay” themselves out. But that’s for later.
Now going back to our problem, the second distribution is more interesting. What if we had a log-normal distribution? Or better yet, let us assume a Log Levy distribution, which is more indicative of financial models (and of the stock market). This would be one where they have sharp peaks (for success) and long-tails (for the long periods of failure).
Since the stocks themselves are likely to show a Levy distribution, it would not be wrong to assume that our quants mirror this pattern.
If that is the case, our graph for a stable Levy distribution would look something like this (courtesy Wikipedia):
Now, we have a few cases to consider. If we consider
then it becomes a normal distribution, which we just talked about. On the other hand, for all other values of
, we could have heavy-tailed distributions.
So, here are my questions –
?Quite obviously, I am trying to back-track from a series of assumptions to evaluate the feasibility of having more than an optimal number of quant-based hedge funds. And I am also interested in evaluating the success and failure thresholds for such numbers.
Finally, I am looking for the Black Swan that will throw these numbers into quant hell.
(Yes, I am quite well aware that this post has a lot of inconsistencies and assumptions, and that I have completely ignored the injection of new blood into the system — quite obviously, this is an exercise in theory, so forgive me while I meander.)
For the first time since 2003, the Federal Reserve lowered its interest rate from 5.25% to 4.75%. Most people expected a cut of maybe 0.25%, but a cut of 0.5% was significantly higher and perhaps underscores the serious concerns about the economy.
While this may not directly affect consumers, this will have an impact on the prime lending rates of most financial institutions in the country. And interestingly enough, the stock market seems to have soared with the news with significant gains.
So, is this merely going to postpone the inevitable or will the extra financial liquidity be used “wisely”?
Personally, I think that this could be a boon for FIIs to invest in other more stable markets (e.g. Asia). This would not necessarily peg the investors to a market that might go into recession in the near future.
Either way, it would be interesting to see how the market reacts to this in the long term.
Paul Kedrosky talks about an interesting NYT article on how hedge funds and private equities seem to change career options for people who might otherwise consider going for an MBA.
The interesting thing about this is the fact that I in fact do know several people who are at those cross-roads.
While being a quant-jock definitely has its advantages in terms of pay and big fat bonuses, it also tends to burn out a lot of people quite fast. On the other hand, all it takes is a few years on the market as a quant and you are set to do whatever you want a wee bit later. But does having that top B-school MBA really help you in those particular areas that you work on, as a quant? That is the more interesting question.
The other thing that came to my mind was this — to what extent does this apply to other areas, besides finance? In IT, going anything above a Solutions Architect (or its equivalent) with just a technology degree is rather hard, in most places. But are there other areas where an MBA does not particularly matter? Say, Biotech?
It would be interesting to see if there are similar patterns in other industries, besides finance.
No, I am not talking about Skyline Chili, although I do love their food. Here is a picture of Cincinnati taken from Newport on the Levee, right across the Ohio River.
There’s nothing better to start off a day with than a good cup of coffee that gets me smiling. But what if your coffee could smile back at you?
That’s right, there are people out there that paint that latte for you with interesting patterns. Check out this interesting video.
And a quick look at Flickr for coffee art also reveals some interesting creations. It’s almost like soldering, only not.
I finally gave into temptation and bought myself a few Lego Bionicle sets. Have a peek.
And is it me or does anyone else think that these two pictures could totally fit into an Alien vs. Predator movie?
I snagged the following screenshot off Nokia’s Nseries website.
Of course, this is probably because they gather generic RSS feeds tagged with Nokia or Nseries and display it on their website, but it is still surprising that a company as large as Nokia would let content seep through to their website that has not been approved by QA folks first.
That said, it is a neat website (if you forget the fact that it’s done in Flash, for a moment). And I am indeed a big fan of Nokia – wouldn’t dream of using any phone other than their’s.
Now, I wonder if my blog entry will show up on their website!
There is an interesting discussion on Yahoo! answers on the fraction of wealth that was created by people, as opposed to those who inherited it.
Any thoughts?
I could not resist putting up this picture of my three little Hexbug critters together.
They are such mean things — they try avoiding one another but in the process, end up hitting one another anyway. Almost makes me want to write a program to see what a colony of a million of these would look like.
We visited the Cincinnati Museum of Natural History & Science yesterday. It was loads of fun. Fun pictures are up on Flickr.
If you haven’t noticed, I suffer from ENS (Excessive Neoteny Syndrome) and lately, I have been obsessed with making various fun things with Lego.
So, here you go – a Lego DeLorean.
I was hacking the Lego Mindstorm vehicle demo when I saw a few other things lying around on my desk. I totally could not resist taking this picture.