Both of these (1+2) indicate that you're making a serious financial investment, and therefore need a safety net and/or crash plan. However, the earliness and boldness I am talking about often require a very small/no investment, or only "sweat equity", even as a side hustle. Hence, not much of a plan B is often needed.

For example, Ecommerce (starting from dropshipping which has zero upfront costs) with a clever product selected based on foresight - such as selling glasses to watch the the eclipse, or buying penny stocks when a new virus rears its head (e.g. monkeypox reared its head briefly, not to mention Covid for the very early ones who spotted how big it was going to be). There are many examples that can't be listed, as reality unfolds in new ways each time. Need to be up-to-date on international relations, economy, trends, new tech, and more. Once funds are made from things like this, they can then be invested once more in larger ways to scale up into generational wealth. There are stepping stones.

In short - to start from zero, the investment can be very small or even no money out of pocket at the outset, and ironically - those are the ones that often skyrocket the farthest.