This was posted in main Nxt thread, might be a good guideline.
Smart Contracts used by Ethereum
http://www.actuss.com/doc/classes.htmlFeatures
ACTUS Contract Calculator
4.1 Principal At Maturity (PAM)
The PAM contract type encompasses many common financial contracts. Most typical representative is the classical government bond. It also covers money market funds, fixed deposits and also all sorts of bullet type loans. Beyond simple fixed rate instruments it accommodates many complex variants such as variable rate instruments and instruments with capitalization.
Principal At Maturity Calculator
4.2 Annuity (ANN)
ANN contract type at its simplest form represents an annuity payment, where principle and interest are paid out over a specified period of time. Common mortgages in several countries follow this pattern. This contract type can represent fixed and variable rate annuities, also including grace period, irregular payments and so on.
Annuity Calculator
4.3 Stock (STK)
A STK contract represents a certain quantity of equity issued by a company.
Stock Calculator
4.4 Future (Futur)
A FUTURE is a standardized contract to buy or sell specified asset at a price agreed upon today with payment occurring at a specified future date. Underlying assets can be Bonds, stocks, commodities or FX rate related instruments. In ACTUS, a FUTUR is represented with a parent-child relationship, with the child being the underlying asset. Closely related to FUTURE is the margining process, which can be modeled in many facets.
Future Calculator
4.5 Swap (SWAP)
A SWAP is a derivative in which counterparties exchange cash flows of one party's financial instrument for those of the other party's financial instrument. In ACTUS, it is represented with a parent-child relationship having two children, which are basic CT’s (such as PAM or ANN). This method of combination of basic CT’s allows ACTUS to represent multiple other variants of swaps, an example being amortizing swaps.
Swap Calculator
4.6 Option (OPTNS)
An OPTION gives the holder the right to buy or sell an underlying asset for a given price (Strike) on or before a specified future date. In ACTUS, it is represented with a parent-child relationship, where the underlying child can be a Bond, stock, commodity or FX rate related instrument. All variants of call/put and American, Bermudan and European options are (or will be) supported in ACTUS.
Option Calculator