One is concerned with defining the following financial concepts in terms of continuous-timeStochasticProcesses:
- Assets: what people/entities own and it’s cash value
- Security: an asset that can be traded. Can be based on debt (a deposit to a bank that is owed to the depositor but can be invested by the bank), on equity (stocks) or on both (hybrid)
- Bond: a bond is a security that is a form of loan/IOU with interest
- Risk: uncertainty about financial returns. Can arise due to various aspects of the market leading to various forms of risk
- Markets: the system in which trading occurs
- Portfolios: collection of investments
- Gains: when the market value of an asset exceeds purchase price. Can be realized (sold for cash) or unrealized.
- Wealth: Collection of assets that can be used for trading/transactions
A financial market is modeled as a collection of stochastic processes on an underlying filtered probability space
- Initial stock prices i.e. share of bond/market. That is continuous,
-adapted, and has finite variation: