Then do you consider only venture-funded technology startups? After all, most of the folks on the technology list got there through venture funding. Do you consider only startups where the founders quit their day job? Do you consider ones where the founders eventually quit their day jobs, but not until their startup had traction in the marketplace? (That would include Apple and EBay, FWIW.) Do you consider any technology project that may become a startup?
The original thread-starter wants to know the chances of making the Forbes 400, given that he becomes a tech entrepreneur or financier. He rightly points out that this depends a lot on the denominator - but the denominator depends a lot on how you slice the categories of "tech entrepreneur" and "financier". There are a large number of factors besides entrepreneurship that alter the odds, and many of them alter the odds a lot more than the mere fact that you've started a company.
The original thread-starter wants to know the chances of making the Forbes 400, given that he becomes a tech entrepreneur or financier. He rightly points out that this depends a lot on the denominator - but the denominator depends a lot on how you slice the categories of "tech entrepreneur" and "financier". There are a large number of factors besides entrepreneurship that alter the odds, and many of them alter the odds a lot more than the mere fact that you've started a company.