What should be consistent when auditing fair values?

When auditing fair values, it is crucial for the method of estimating to be consistent. This consistency ensures that the approaches used in estimating fair values are applied uniformly across similar transactions or periods, which enhances the comparability and reliability of the financial statements.

Using a consistent method helps to reduce the risk of error or bias in the estimates, making the audit process more effective and the results more credible. Consistency in the chosen valuation method allows auditors to better assess the reasonableness of the estimates made by management, and it also aids in understanding how different assumptions and inputs impact the fair value calculations.

The other elements mentioned, such as market trends, acquisition costs, and the auditor’s opinion, are important in their own right but do not directly relate to the consistency required in the estimation process. Market trends may vary over time and can affect fair value measurements, while changes in acquisition costs can influence valuations as well. The auditor's opinion is an ultimately subjective judgment and could be impacted by various factors, but it does not dictate a consistent metric for valuing assets or liabilities. Thus, consistency in the estimation method remains the key focus in ensuring the reliability of fair value audits.