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Statistics for Financial Engineering. Part1: Probability Instructor: Youngju Lee MFE, Haas Business School University of California, Berkeley. Overview of Class. Part1: Probability – March 23 rd , 2006 Part2: Statistics – March 25 th , 2006 Class will be organized as Definitions
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Statistics for Financial Engineering Part1: Probability Instructor: Youngju Lee MFE, Haas Business School University of California, Berkeley
Overview of Class • Part1: Probability – March 23rd, 2006 • Part2: Statistics – March 25th, 2006 • Class will be organized as • Definitions • Some comments about from definition • Problems • Applications in financial engineering – I will give short examples how I apply these concepts in my real life and practice since I assume you do not have any idea about financial engineering as of now.
Probability • Probability • Random Variables – Discrete and Continuous • Distribution and Probability Density • Moments and Moments Generating Function • Stochastic Independence • Basic Limit Theorem
Probability Definition1
Probability Some consequences of definition 1
Probability Try this
Probability In finance world? • This is the very basic concept of everything. – States, Monte-Carlo simulations and Binomial Trees, etc.
Conditional Probability Definition 2
Conditional Probability Some consequences from definition 2
Conditional Probability Try this.
Conditional Probability In finance world? • Fancy empirical model – Regime Switch Model
Independence Definition 3
Independence Some consequences from definition 3
Independence Try this. – Easy! Six fair dice are tossed once. What is the probability that all six faces appear? Seven fair dice are tossed once. What is the probability that every face appears at least once?
Independence In finance world? Is there any independent event in the financial world or at least in practice?
Random Variables Definition 4
Discrete Random Variable Definition 5: Binomial distribution is associated with binomial experiments – success or fail
Discrete Random Variables Definition 6: Poisson distribution
Discrete Random Variables Definition 7: Discrete uniform distribution
Discrete Random Variables Definition 8: Hyper-geometric distribution
Discrete Random Variables Definition 9: Negative binomial distribution
Discrete Random Variables Definition 10: Multi-nominal distribution
Continuous Random Variables Definition 11: Normal distribution
Continuous Random Variables Some consequences from definition 11 • Normal distribution is symmetric. • Normal distribution has maximum value at mean.
Continuous Random Variables Try this.
Continuous Random Variables In finance world? Everything is assumed normal distribution in financial engineering. To check normality, Use K-S test or Normal Probability Plot. I will cover this later.
Continuous Random Variables Definition 12: Gamma distribution
Continuous Random Variables Definition 13: Chi-square distribution
Continuous Random Variables Definition 14: Negative exponential distribution
Continuous Random Variables Definition 15: Continuous uniform distribution
Continuous Random Variables Definition 16: Beta distribution
Continuous Random Variables Definition 17: Cauchy distribution
Continuous Random Variables Definition 18: Lognormal distribution
Continuous Random Variables Definition 19: Bi-variate normal distribution
D.F. and P.D.F. Definition 20: The distribution function
D.F. and P.D.F. Some consequences from definition 20
D.F. and P.D.F. Try this. – It is better to know what logistic distribution is.
D.F. and P.D.F. In finance world? You probably want to remember some consequences from last slide. We use this all the time to make trading signals.
D.F. and P.D.F. Definition 21: Joint distribution function
D.F. and P.D.F. Definition 22: Quantile of a distribution
D.F. and P.D.F. Definition 23: Mode
D.F. and P.D.F. Try this. Let X be an r.v. with p.d.f. f symmetric about a constant c then show c is a median of f.
D.F. and P.D.F. In finance world?
Moments Definition 24: Moments of random variables
Moments Some consequences from definition 24
Moments Try this. A roulette wheel has 38 slots of which 18 are red, 18 black, and 2 green. Suppose a gambler is placing a bet of $M on red. What is the gambler’s expected gain or loss and what is the standard deviation?
Moments Try this. But do not calculate! Let X be an r.v. taking on the values -2,-1,1,2 each with probability 0.25. Set Y=X*X and compute the following quantities. EX, Var(X), EY and Var(Y).
Moments In finance world? I do not think you can be in finance industry without talking about Sharpe ratio a lot. (mean/sd) We also need to look at skewness and kurtosis.
Stochastic Independence Definition 25: Stochastic independence
Stochastic Independence Some consequences from definition 25