Definitions Flashcards
(31 cards)
Arrow-Debreu security (state contract)
a financial contract for a certain state j, bought at time 0, that pays one unit of income at time 1 if state j realizes
State price
π_j, the price of a state contract at time 0 that pays off one unit of income at time 1 if state j realizes and zero otherwise. (i.e. the price of a state contract)
Discount factor
π(1) = 1/(1+r), where r is the interest rate. This factor shows the amount that one unit of income at time 1 is worth at time 0
Interest compounding (discrete)
d_i = 1/(1+r_i)^i
Interest compounding (continuous)
d_i = exp(-r_i*i)
Implied probabilities/normalized prices/risk-neutral probabilities
denoted by q_j = π_j/(sum(π_i)), where π_j is the state price for state j
Normalized pricing kernel
θ_j=q_j/p_j, where q_j is the normalized price of state j and p_j is the objective probability that state j realizes
Pricing kernel/Stochastic discount factor (SDF)
M_j=π(1)q_j/p_j, where π(1)=1/(1+r) represents the price of a contract that pays one unit of income for certain, no matter what state realizes and q_j/p_j is the normalized pricing kernel
Aggregate income
Total income of all agents (i=1,…,k) together in state j
Market clearing condition
the condition that for each traded asset, total demand equals total supply. If this is the case, we speak of a general equilibrium
Dynamic strategies
a kind of trading strategy. This may involve trading at periods different from the current one.
Liquidity
A liquid asset is easy to buy or sell, for example stocks of large companies and government bonds. Illiquid assets are privately owned companies, large real estate objects and collector items in art.
Liquid market
a market in which all contracts are liquid; all contracts can be easily bought and sold at any time for a fixed price
Efficient market
a market is said to be efficient if all relevant information is available and adequately processed by all market participants. In an inefficient market, some traders have an information advantage
Utility function
u(x), a function of an agent that describes the value associated to hold a certain commodity or money by this agent
Coefficient of absolute risk aversion
this coefficient tells the degree of risk aversion for an agent at some wealth level x: R(x) = -(u’‘(x)/u’(x))
Rationality
agents take their decisions on the basis of a principle that can be expressed in terms of optimization of the utility function
Complete market
A market is complete if every possible cash flow sequence can be generated by the cash flows of the basic assets. This happens when there is a unique solution to the vector-matrix equation Fd=π
Replication
Given a collection of series of future cash flows, we say that a series of cash flows is replicable if there exist numbers x_1,…,x_m, such that sum(x_j*f_ji)=f^_i for all i=1,…,n
Hedging
a trading strategy that is aimed to reduce the risk that is associated with a given contractual obligation. For perfect hedging there must be a complete market and exact model
Arbitrage
a trading strategy that, with a positive probability, generates a positive cash flow either immediately or at some point in the future, and that does not generate any negative cashlows
Strict arbitrage
a trading strategy that, with a positive probability, generates a positive cash flow immediately and that does not generate any negative cashlows
Call option
gives the holder the right, but not an obligation, to buy an underlying asset for a pre-specified price K (strike price). Let S_gamma be the stock price at a certain possible state in time gamma and K be the strike price. The pay-off is then Call_gamma = max(S_gamma-K,0)
Put option
gives the holder the right, but not an obligation, to sell an underlying asset for a pre-specified price K (strike price). Let S_gamma be the stock price at a certain possible state in time gamma and K be the strike price. The pay-off is then Put_gamma = max(K-S_gamma,0)