Comparing WACC Calculator Results with Professional Financial Terminals: Bloomberg vs Refinitiv Parameter Differences

The weighted average cost of capital (WACC) is the single most consequential input in any DCF valuation, yet a widening divergence between the outputs of standard online calculators and professional financial terminals is creating a hidden risk for Hong Kong-listed issuers and their advisors. Since the HKEX’s enhanced Listing Rule amendments on connected transactions and financial assistance disclosure took full effect in January 2025 (HKEX, Consultation Conclusions on Review of the Listing Rules, December 2024), the SFC has increased its scrutiny of valuation methodologies used in circulars and prospectuses. A WACC mis-specified by even 50 basis points can swing an impairment test or a fairness opinion by HKD 200 million or more for a mid-cap Main Board issuer. The core problem is not arithmetic—it is parameter selection. Bloomberg’s WACC function (WACC) and Refinitiv’s (Eikon) treat the cost of equity, the risk-free rate, and the equity risk premium (ERP) as fundamentally different variables, creating a systematic gap that analysts must reconcile manually. This article dissects the three critical parameter differences—risk-free rate tenor, ERP methodology, and the treatment of the Hong Kong-specific illiquidity premium—and provides a reconciliation framework grounded in the SFC’s Code on Takeovers and Mergers (2024 edition) and HKMA’s Supervisory Policy Manual (CA-S-2, 2023).

The Risk-Free Rate: Hong Kong Exchange Fund Notes vs US Treasury Yields

The choice of risk-free rate is the first major divergence between Bloomberg and Refinitiv, and it directly impacts the cost of equity calculation under the Capital Asset Pricing Model (CAPM). Bloomberg’s default WACC function for Hong Kong issuers typically uses the 10-year US Treasury yield as the proxy for the risk-free rate, adjusted for the cross-currency basis swap. Refinitiv’s Eikon, by contrast, defaults to the 10-year Hong Kong Exchange Fund Notes (EFN) yield. As of 30 September 2025, the 10-year US Treasury yielded 4.12%, while the 10-year EFN yielded 3.58%—a 54-basis-point differential that, when multiplied by the beta and ERP, produces a material gap in the final WACC.

The HKMA’s position on this is explicit. In its Supervisory Policy Manual module CA-S-2 (revised 2023), the HKMA requires authorised institutions to use “a risk-free rate consistent with the currency of the cash flows” when conducting impairment assessments under HKFRS 9. For a Hong Kong-listed company reporting in HKD and generating the majority of its cash flows domestically, the EFN yield is the regulatory-preferred benchmark. However, many online WACC calculators—including those embedded in free financial data platforms—lack the EFN data feed entirely and default to the US Treasury, overstating the risk-free rate by 50–60 bps.

The practical consequence for Hong Kong CFOs is a systematic upward bias in WACC. An issuer with a beta of 1.2 and an ERP of 6.5% would see its cost of equity drop from 11.92% (using US Treasuries) to 11.38% (using EFNs) solely due to this parameter change. Over a 10-year DCF with a terminal value, this 54-bps reduction in the discount rate can increase the enterprise value by approximately 8–12%, depending on the free cash flow profile. Analysts relying on Bloomberg’s default setting without manual override are effectively undervaluing Hong Kong-domiciled issuers relative to the HKMA’s prescribed framework.

Equity Risk Premium: Historical vs Implied Methodologies

The second major parameter divergence lies in the equity risk premium (ERP), where Bloomberg and Refinitiv employ fundamentally different estimation methods. Bloomberg’s WACC function defaults to a historical ERP, typically the long-term arithmetic average of the excess return of the Hang Seng Index (HSI) over the risk-free rate, calculated over a 20-year rolling window. As of Q3 2025, this historical ERP for Hong Kong stood at 6.8%. Refinitiv’s Eikon, conversely, uses an implied ERP derived from the dividend discount model (DDM) on the HSI, which as of the same date produced an implied ERP of 5.2%—a gap of 160 basis points.

The SFC’s Code on Takeovers and Mergers (2024 edition) provides indirect guidance on this choice. In Note 3 to Rule 11.1, the SFC requires that financial advisors providing fairness opinions on general offers must disclose the “key assumptions and parameters used in the valuation, including the discount rate and its components.” The Code does not mandate a specific ERP methodology, but it does require that the methodology be “appropriate to the circumstances of the offeree company and the prevailing market conditions.” For a cyclical Hong Kong property developer, the historical ERP (6.8%) may be more appropriate because it captures the full cycle of boom and bust. For a stable utility or infrastructure issuer with regulated cash flows, the implied ERP (5.2%) better reflects current market pricing.

The divergence creates a reconciliation problem for cross-border investors. A family office using Bloomberg’s historical ERP will derive a WACC of approximately 10.2% for a typical Main Board consumer stock, while the same analyst using Refinitiv’s implied ERP will arrive at 8.8%. Neither is “wrong” per se, but the 140-bps gap is larger than the typical margin of error that the SFC would accept in a fairness opinion without explicit justification. The practical takeaway is that any WACC used in a regulatory filing must be accompanied by a sensitivity table showing the impact of both ERP methodologies, as a single-point estimate is no longer defensible under current SFC scrutiny levels.

The Hong Kong Illiquidity Premium: A Parameter Most Calculators Ignore

The third critical parameter difference—and the one most frequently omitted from online calculators—is the illiquidity premium specific to Hong Kong-listed small- and mid-cap stocks. Neither Bloomberg’s WACC nor Refinitiv’s WACC function includes an automatic adjustment for liquidity, yet the HKEX’s Guidance Letter GL86-16 (updated 2024) explicitly notes that “the discount rate used in impairment reviews should reflect the liquidity risk associated with the underlying assets or cash-generating units.” For a company listed on the Main Board but with an average daily turnover of less than HKD 5 million, the liquidity discount embedded in the cost of equity can range from 100 to 250 basis points, depending on the bid-ask spread and trading volume.

The academic literature supports this adjustment. Damodaran’s 2024 update on country equity risk premiums includes a liquidity sub-premium for Hong Kong small-caps of 1.8%, derived from the difference in bid-ask spreads between the top 20 and bottom 200 stocks by market capitalisation on the HKEX. The HKMA’s Guideline on the Management of Market Risk (2022) also requires banks to incorporate a liquidity premium when valuing unlisted or thinly traded equity exposures under the internal ratings-based (IRB) approach.

The practical implication is that online WACC calculators systematically understate the cost of equity for Hong Kong small-caps. A typical GEM-listed technology company with a beta of 1.5, an ERP of 6.5%, and a risk-free rate of 3.58% would have a base cost of equity of 13.33% under CAPM. Adding a 180-bps illiquidity premium brings the true cost of equity to 15.13%. This 180-bps gap is material enough to change the outcome of an impairment test under HKAS 36, where a recoverable amount falling below the carrying value by less than 10% is often the threshold for triggering additional disclosure or a full impairment charge.

Reconciliation Framework for Hong Kong Practitioners

Given the three systematic parameter differences—risk-free rate tenor, ERP methodology, and illiquidity premium—a standardised reconciliation framework is essential for any WACC used in a regulatory filing or investment committee paper. The following approach aligns with both the SFC’s Code on Takeovers and Mergers and the HKMA’s Supervisory Policy Manual.

Step one: Establish the base case using the HKMA-preferred EFN yield. For any Hong Kong-domiciled issuer reporting in HKD and generating domestic cash flows, the 10-year EFN yield is the correct risk-free rate. This should be sourced directly from the HKMA’s daily statistical bulletin (Table 3.1) rather than from a terminal, as terminal feeds may lag or use interpolated data.

Step two: Run both ERP methodologies and present a range. The historical ERP (Bloomberg default) and the implied ERP (Refinitiv default) should both be calculated, and the final WACC should be presented as a range rather than a point estimate. For the fairness opinion context, the SFC expects the midpoint of this range to be used as the primary discount rate, with the endpoints shown in a sensitivity table.

Step three: Apply the illiquidity premium explicitly. The premium should be calculated using the stock’s average daily turnover relative to the Main Board median, with a floor of 0 bps for liquid large-caps and a cap of 250 bps for illiquid GEM stocks. This adjustment must be footnoted with reference to the bid-ask spread data from the HKEX’s Monthly Market Statistics.

Step four: Cross-validate against the implied cost of capital from the stock’s own trading data. The inverse of the forward P/E ratio, adjusted for expected growth, provides a market-implied cost of equity that should fall within the range derived from the CAPM. If the implied cost of equity is outside the CAPM range by more than 100 bps, the analyst must revisit the beta estimation period or the ERP assumption.

Actionable Takeaways for Hong Kong CFOs and Advisors

1. Always override Bloomberg’s default risk-free rate to the 10-year EFN yield for Hong Kong-domiciled issuers, as the HKMA’s CA-S-2 (2023) explicitly requires currency-consistent risk-free rates for impairment testing.

2. Present WACC as a range, not a point estimate, using both Bloomberg’s historical ERP (6.8%) and Refinitiv’s implied ERP (5.2%) as boundaries, and include a sensitivity table in any circular or fairness opinion filed with the SFC.

3. Quantify and disclose the illiquidity premium for any issuer with an average daily turnover below HKD 10 million, referencing the HKEX’s Monthly Market Statistics and the bid-ask spread data from the exchange’s public feed.

4. Cross-validate the final WACC against the stock’s implied cost of equity derived from the forward P/E ratio and expected growth rate, and document any discrepancy exceeding 100 bps in the valuation methodology section of the filing.

5. Update the WACC parameter assumptions quarterly to reflect changes in EFN yields, HSI dividend yields, and the stock’s own trading liquidity, as the SFC’s enhanced disclosure requirements under the 2025 Listing Rule amendments demand current, not static, inputs.