An investor you are talking to believes in efficient markets fervently, such that it is impossible to find 'Alpha'.This investor instead believes that all assets have zero alpha, and are only separated by their betas (degree of market risk). This investor implicitly believes:

		that Markowitz Mean-Variance optimization is the ideal way to invest and select portfolios.
		that the returns of all securities fall on the SML (security market line).
		that the Sharpe Ratio is the ideal risk-return metric.
		that the CAPM should never be used.