The VMarket applet is a pedagogical tool showing how the price of financial derivatives can be calculated using a variety of different methods. Tag modifiers define the default behaviour of an applet: the selectors on the top of the applet switch between different types of simulations and the parameters on the right attribute specific values.

Press the Start / Stop button to execute the VMarket applet until the value of the Time reaches the value RunTime or Step 1 to take unit steps of a duration TimeStep. Different functions are evolved (depending on the simulation) and are displayed in the plot window; approximative measurements can be read from the browser status bar after clicking in the plot window and are also printed to the Java console. Far more accuracy can be obtained by pressing the Print Console button and by reading the numerical output from the Java console:

The selectors appearing on the top of VMarket applet define the type of problem. They are initialized with default values and are later modified to fit the values specified in the Tag window. Careful, white spaces count!

Run parameters.
The parameters appearing in a list on the right side of the VMarket applet are initialized with default values and are later modified to fit the values specified in the Tag window. They can be modified even later at run time by double-clicking the names. Note that only the parameters specified in the list of Tag modifiers (thought to be relevant) are listed. For a complete list at run-time, switch the selector from Double click below to Show all parameters.

HTML TAG modifiers format.
The VMarket applet is insearted in an HTML document via the Tag window using a header of the form

<applet codebase="$user_dir/applet/" code=vmarket 
    align=center width=780 height=420>
    <param name=topic               value="Exercise">
    <param name=scheme              value="Exercise 4.07">
    <param name=ic                  value="Put">
    <param name=method              value="FinDifferen">
    <param name=RunTime             value= 0.5>
    <param name=Drift               value= 0.1>
    <param name=Volatility          value= 0.4>
    <param name=LogNkappa           value= 1.>
    <param name=SpotRate            value= 0.1>
    <param name=Dividend            value= 0.>
    <param name=StrikePrice         value= 10.>
    <param name=Barrier             value= 0.>
    <param name=MktPriceRsk         value= 1.>
    <param name=MeanRevTarg         value= 0.05>
    <param name=MeanRevVelo         value= 0.1>
    <param name=Shape0              value= 6.>
    <param name=Shape1              value= 4.>
    <param name=Shape2              value=-2.>
    <param name=MeshLeft            value= 0.>
    <param name=MeshLength          value= 20.>
    <param name=MeshPoints          value= 100>
    <param name=Walkers             value= 300>
    <param name=TimeStep            value= 0.00397>
    <param name=TimeTheta           value= 0.7>
    <param name=TuneQuad            value= 0.333>
    <param name=UserInt             value= 0>
    <param name=UserDouble          value= 0.>
The first two lines specify the path name on the server, the position and the size of the window. The Tag modifiers that follow attribute the values that will be set when the applet first appears in the web page. These can always be recovered simply by refreshing the webpage.