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Why Required and Expected Returns Align in CAPM Valuation

Article Quant Q&A · Author: shenflow

Summary

The document explains why discounted cash flow valuation commonly uses a CAPM-based required return that is also treated as an expected return. Under the model, investors require compensation for waiting and for bearing market risk. If they believe CAPM correctly describes that compensation, a return below the model-implied rate would not attract investment. With uncertain returns and rational expectations, the expected return follows from the same relationship; CAPM can also be read statistically as a model for expected returns.

The second explanation is market equilibrium. If the market requires more than it expects to earn, demand falls and the price declines, raising the prospective return until it meets the required return. If expected return exceeds what investors require, buying pressure raises the price and lowers the prospective return. These are market-wide concepts, not claims that an individual investor's personal forecast and hurdle rate must match. The argument depends on assumptions about shared expectations, investor behavior, and equilibrium; the document does not assess whether CAPM is empirically adequate.

Key ideas

  • In CAPM, required return represents compensation for the risk-free time value of money and market risk.
  • If investors accept CAPM as their pricing model, its implied required return also determines their expected return.
  • Market prices adjust when expected returns differ from investors’ required returns, tending to bring them into alignment.
  • The equilibrium explanation concerns market expectations and requirements, not necessarily those of any one investor.

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Full text
# Expected vs required return in valuation


# Expected vs required return in valuation












This is a rather simple question, so this is maybe not the right place, but...

I have done quite a bit of reading on predicting asset returns, i.e. determining return expectations. I have now started reading some fundamental literature on DCF valuation. For example, one might perform company valuation by doing as follows:

\begin{equation} EquityValue= \Sigma^T_t\frac{FTE_{t}}{(1+k^e_{t})^t} \end{equation}

where $FTE_i$ denotes the expected free cash flow to equity holders in period $t$, $k^e_t$ denotes the required rate of return on equity (of that firm) for the respective period $t$.

What I do not fully understand is: Usually textbooks will say that one estimates $k^e_t$ by means of the CAPM. In other words, required return on equity is assumed to be equal to the expected return on equity (derived via the CAPM). I am not trying to start a discussion on whether the CAPM is an appropriate model for deriving expected returns. What I do not get is: Why is the required return assumed to be equal to the expected return? What I expect and what I require are conceptually completely different to me.

## Answer by 1muflon1 (score 2, accepted)

https://quant.stackexchange.com/a/73926

> Why is the required return assumed to be equal to the expected return?

Required return in a model depends on how you model agent's behavior and beliefs.

If you assume agents in a model consider CAPM the correct model of asset pricing, that is they all believe CAPM is the correct description of how returns should be related to market risk and opportunity cost of money, then no agent would accept return lower than the return given by CAPM. If the return would be lower they would simply not invest according to the model.

From economic perspective when CAPM is used to model agent's behavior, CAPM can be viewed as:

$$\underbrace{r_i}_{\text{required return}} = \underbrace{r_f}_{\text{compensation for impatience }} + \underbrace{b_i(r_m−r_f)}_{\text{compensation for risk}}.$$

If we introduce randomness into the model by making $r_i$ and $r_m-r_f$ random variable and people believe this is the correct model then this will also be return given by rational expectations (you can just take expectations of both sides).

Alternatively if we assume that CAPM is the 'correct' statistical model to model returns the we also can reinterpret the CAPM model as a regression model where you regress $r_i$ on $r_m-r_f$ making $r_i$ the expected return.

## Answer by Richard Hardy (score 2)

https://quant.stackexchange.com/a/73846

Expected and required have to be equal in equilibrium. These are market expectations and requirements, not yours, though (but we assume that everyone shares the same expectations). So if the market requires more than it expects, the demand for the stock will go down, taking the price with it, so that the return will grow – until the expected value matches the required one. And if the market expects more than it requires, the demand for the stock will go up, taking the price with it, so that the return will shrink – until the expected value matches the required one.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.