Initial concept

The 18XX stock market on the 1830 branch is delightfully simple. It is a rectangular grid arranged on a roughly extended triangular shape. A given company has a price per share on the chart. The mechanisms are simple:

1) If the company pays dividends to its investors then its stock pice moves one to the right (and thus increases in value)

2) If the company withholds its dividends (likely to accumulate cash for internal investment), then the share price moves left on the chart and thus decreases in value

3) If a player sells one or more shares of the company then the stock price moves down on the chart, down one row for each share sold. The selling player receives the full price the shares were at when he initiated his sale

4) If all the shares in a company are owned by players then the stock pricemoves up by one row

5) If in moving right the edge of the grid is reached, then the stock price moves up a row instead

6) If in moving left the edge of the grid is reached, then the stock price drops a row instead

7) Companies which reach the lower left corner are removed from the game

8) The values in the upper rows are more widely separated than the values in the lower rows. Similarly the values further to the right are more widely separated than to the left. The result is that the profit from a stock value increase further right and up and larger than lower and left

So. Let’s rip out the trains and the companies and leave just the stock market mechanisms, and then replace the train game with a speculative stock/set-collecting game. Market actions on trade goods (purchases, sales, dumps, etc) can drive the right/left/up/down motion in very similar fashion. The goal is to arrange a reasonably simple and light weight set of mechanisms to provide an interesting speculation game atop the stock market game.