Mavaron's Twitter

    follow me on Twitter

    2008-11-28

    Replicate the success of Shrek?

    http://www.apple.com/trailers/dreamworks/monstersvsaliens/


    Michael Rabin

    I have only one word to say about Michael Rabin's violin skills: impeccable. 

    2008-11-26

    深交所

    I admire those who start things from zero. Divide and conquer, this is real fun. 

    http://www.chinavalue.net/Article/Archive/2005/11/7/13342.html

    打油诗

    一杯茶,一包烟,一支烂股盯半天
    一分钱,一份闲,一批散户套半年

    Rounding tricks

    number theory day. another problem for fun. 

    think about the bank. their system is with a minimal unit: 0.01, or, a cent. So any more decimal places would be rounded using the most common rule: 0-4, round down; 5-9, round up. 

    so think about the following two scenarios:

    1. Bank lends 0.1 to A, charging 6.31% annually. This 0.1 comes from two resources, a 0.05 deposit from B and the left 0.05 deposit from C. The deposit rate, for simplicity, also assumed to be 6.31%. Then what would be left in the bank after one year?

    Not zero. The correct answer would be: (RND means round the number)
    RND{ 0.1 * ( 1 + 6.31% ) } - 2 * RND{ 0.05 * ( 1 + 6.31% ) } = 0.11 - 2 * 0.05 = 0.01 

    Well, you can say it's trivial. Who would give a damn to the 1 cent, especially for the bank. So let's see another example:

    2. You have 160,000 to deposit into a bank with 3.14% annual deposit rate. What would you expect?

    The answer may not be the most common one: 160,000 * ( 1 + 3.14% ) = 165,024. Let me show you another trick.

    You split your money into pieces each with identical amount: 0.16. So for each piece, the finaly amount after a year would be RND{ 0.16 * ( 1 + 3.14% ) } = 0.17. Thus you would get 0.17 * 10^6 = 170,000. Compared with previous 165,024. An extra 4,976 is in your pocket. And that equals to a 6.25% annual rate. 

    Of course, there are many limits in the bank. And my example is not to teach you to arbitrage, but to show you how a badly designed system could damage. 

    I won't bother to explain the math after the two examples. Just for fun. 

    Little problem for fun

    just watched a video talking about Euler and his works. so post a little problem for fun in memory of this great mathematician. 

    given a series of digits within {0,1,...,9} and operators to be taken in {+,-,*,/}. you can use () to change order arbitrarily. the ultimate goal is to form an equality between the left and right sides. 

    a few examples:

    22 => 2=2
    235 => 2+3=5
    4221 => 4/(2+2)=1

    rules:

    1. there must be one and only one operator between two consecutive digits. so 4*6=24 is illegal. 
    2. there might be multiple some equalities, like 2221 => 2/2=2-1, 2-2/2=1. it's ok. as long as you can find one. still count as one.  

    so here comes the problem. given a 2-digit pair, of course there are only 10 such equalities. then what about 3-digit, 4-digit, 5-digit? and what about 100-digit? how many serials we can find such equalities?

    just a problem for fun. anyone who sends the answer (with a reasonable logic other than brute force) will win a good gift.

    thanks for playing. 

    2008-11-11

    Decode IBFX contest (I)

    IBFX is holding a contest for its mini account which requires a min 250 deposit. The contest is calculated each month based on percentage return. Top 5 would be awarded cash directly. 

    Several interesting thing can be observed from the historical results. 

    1. The top 5 or so usually would dramatically outperform the other guys. They usually would at least double their assets. The top 100 can at least have a 10% return. 

    2. There are always guys who blow up their whole assets. Even worse, someone can lose more than they have. This may be due to a terrible bet on the Friday close. 

    3. If the contest participants can be viewed as rational sample of the traders at IBFX. Then definitely the broker woule earn a considerable amount from both spread taking and holding the opposite portfolios to the traders'.


    Plateau

    At triple point, finally there shows some stagnation. Is this because of human weaknesses or over exploration of my profitable patterns? In either case, time to do some review and summary.

    Break, we need. 

    2008-11-06

    Is now the right time to buy corporate America?

    The election of Obama may not appear as beautiful as it seems. Too many and too chaotic expectations are put on him. But from another angle, as the old wall street saying goes, timing is everything. Obama knows this well. There is still room for the downside of American economy. But waiting for another 4 years probably would cost his opportunity to become Roosevelt. Risk is there, but the reward is pretty lucrative.

    If we view the election as trading, then it's just a game that you can only access at limited openings. What's more, your opponent would only make you more risk seeking.

    It's not the right time to buy America now. But for Obama, I would say he is lucky to be chosen at this historical time.

    2008-10-25

    A simple explanation of the 5% rule

    Many asked me about the 5% rule I said in previous post. Let's get some clue from simple examples.

    In short, this is just some analogous version of the notorious doubling strategy used in option trading. In forex market, there could be some sudden move which is highly unpredictable and contradicted to long-term trend. Mostly, such move would be controlled within 2% range, which, take EUR/USD as example, is some 200-250 pips move. That is to say, given a 100 margin ratio, you are going to be eliminated if your position is over half of your asset (I mean the margin you use). What's more important is such move usually happens in less than 5 minutes, maybe without even a look back. For guys like me who can't concentrate on the market all the time, such move is deadly.

    So taken the famous Fibonacci rule, there might be a 30% correction before next major move. So make it safe, let's say 20%. Then if we assume you only buy before the move and at the bottom of the move, an asset allocation about 1:4 would be appropriate. Still in pursuit of simpleness, let's just divide it by two to reflect your risk attitude. That's 5%.

    Of course this analysis is too naive. In practice there are tons of variations to reflect your own strategy and risk tolerance. For me, I would use a 1% per trade at most. And what's more important than this in trading is some other principles like strict stop loss, macro analysis, etc. Anyway, the risk control of this means should be appriaciated.

    Probabilistic trader

    All investment books will tell you some methods to make you a millionaire. But everybody knows this is not the truth. Logically, this is for sure in terms of real money. But this may also been explained by adaptive market hypothesis.

    A trader will create self-autocorrelation by taking his past trading record into consideration. A loss will turn him into hesitation at another several trades. This implicitly creates the resonance, which can be described as some emerging order as in Strogatz's "SYNC".

    Such resonance has a tendency to eliminate any profitable short term trading patterns. That's why trending following is so popular. Finally we need some external stimulus to support our speculation.

    2008-10-24

    Double in Two Days

    This post is to memorize the doubling of my trading asset in two days, first time in my trading life. What's good is this is achieved with strict risk control and without a single crazy bet. Is this a signal that my up trend has begun or just the peak of another cycle? Let's wait and see.

    At least I am going to have a happy weekend. Thank you, Mr. Depression.

    Trading

    Currency trading is pretty much alike real life. Any time, only risk at most 5%, or say, release 5% of your temper. Or else, there is great risk to ruin yourself.

    Remember what Lipschutz says, don't be shaken out by noise.

    2008-10-20

    谢晋

    Death of a director, gone the memory of a generation.

    Fischer Black and the revolutionary idea of finance

    A terrific biography of Fischer Black. Highly recommend to those who want to have a taste of development of modern economic theories.

    2008-10-16

    Best time in 40 years

    Looking back at history, all turmoils are perfect materials for great movies, books, ideas and reforms. Can't wait to see them.

    2008-09-29

    The final bullet

    The life as a trader, it seems you are always waiting, no matter how successful you have been, for the final black bullet that will catch you, and catch you hard.

    Just don't forget to smile when you fall down.

    2008-09-26

    Chimay Triple


    Golden color and fruity aroma.

    black swan redemption

    black swan redemption

    for day
    for night
    i'm praying
    for the sacred redemption

    redemption comes
    just as seldom as
    appearance of black swan

    black swans stroll around
    frequent and unperceived

    since we are
    are busy praying
    for appearance of
    the black swan