Most valuation stops at a single number — “it's worth $97.” But two stocks both “20% undervalued” aren't the same investment if one gets there in a year and the other in ten. The sharper question, the one Sven Carlin builds his whole method around, is expected return: buy at today's price, and what annual return will the business's own cash flows deliver from here?
It's the discounted-cash-flow model run backwards on the discount rate. A DCF asks “at a 9% required return, what's it worth?” Expected return asks “at today's price, what return am I actually being offered?” If a business's realistic cash flows only support 4% a year from the current price, you can own a wonderful company and still make a mediocre investment — because you overpaid. If they support 12%, the price is doing you a favour.
This turns “expensive” and “cheap” into something you can act on. A required-return hurdle — Carlin uses 10% — becomes a filter: if the price implies less than your hurdle, you pass, however good the business. It also kills the temptation to chase. A great company at a great price and the same company at a terrible price are different investments, and expected return is what tells them apart.
Because the future is a range, not a point, it's honest to run it three ways — a bear case, a base case, and a bull case — and read the return each implies. This site shows you that spread instead of a single confident figure, because the width of the range is itself information about how much you're guessing.