I did a long write-up on some of the ways runners can invest (read: borrowed and extensively modified some information others had posted about on the web) and came up with this:
http://eveslist.crisses.org/Services/FinancialFor the "Single Corporation Stock (risky,volatile)" method, I created a
Numbers '08 spreadsheet (zip) that helps calculate stocks (and
an export for Excel (xls) -- no guarantees!)
In the spreadsheet I have the top 8 corps from the old Corporate Shadowfiles listed, but not individual divisions + Biogene because my players had run through DNA/DOA and wanted to invest in Biogene stock.
I'd like some feedback, and I thought some gamers/GMs would find it helpful. In tests, stocks have a general tendency to go upwards. One could alter the table for smaller corporate stocks (lower the dividend %, lower the +/- % by half I think), but if your runners are investing in the Big 10, these charts are definitely a start.
To determine a "market boom" or a "market dip" I calculated all the top stocks: if they all gained last month, investor confidence in the market is high and that gives the "market boom" bonus to this month. [Note: I did NOT have Numbers roll randomly for me. Make one change in the chart and it re-rolls. OUCH. Someone with Excel might test whether Excel does the same with random numbers and make the corrections if needed.]
Note: there's no way to really accurately or appropriately address all issues in stock markets. None of this reflects daily trading, and a great stock investor could do better than those charts (perhaps a + daily modifier if you have the right broker -- who will extract a steeper commission I'm sure).