Acciona has meaningful investment needs, but the case for a large hybrid-bond program over the next 18 months is not compelling.

Key considerations:

- **No prior hybrid issuance:** Acciona has never issued hybrid bonds and did not issue them in 2021 or 2022. This is a strong negative signal under the stated guidance, because prior use of hybrids is a strong indicator of future advisable use. A first-time hybrid issue is possible, but the hurdle should be higher.

- **Capex and funding needs are elevated:** 2022 investing cash outflow was large at about **€1.94 billion**, including **€2.20 billion** of purchases of PPE, intangibles, investment property, and other noncurrent assets. This reflects Acciona’s capital-intensive infrastructure and energy profile. Operating cash flow was strong at **€1.65 billion**, but did not fully cover investing outflows, leaving reliance on external financing.

- **Debt increased, but liquidity remains solid:** Gross financial debt-like balances rose materially. Noncurrent bonds/marketable debt increased from **€2.36 billion to €3.10 billion**, noncurrent loans from **€2.07 billion to €2.62 billion**, while current bonds were **€1.14 billion** and current loans **€0.55 billion**. However, cash and equivalents remained high at **€2.36 billion**, broadly stable year on year.

- **Leverage pressure exists, but is not clearly acute:** Reported equity increased from **€5.56 billion to €6.30 billion**, and profitability improved: operating profit rose to **€1.33 billion**, net profit to **€615 million**, and operating cash flow improved sharply. Without S&P-adjusted debt/EBITDA or FFO/net debt data, there is insufficient evidence that investment-grade preservation is strongly dependent on hybrid issuance.

- **Hybrid cost environment worsened in 2022:** Euro swap rates rose sharply in 2022, with 5-year swaps around **1.73%**, 7-year around **1.81%**, and 10-year around **1.93%**, versus negative or near-zero levels in 2020–2021. Subordinated spreads also widened. For a first-time issuer, hybrids would likely be meaningfully more expensive than senior debt and would increase average funding cost.

- **Potential benefit is real but moderate:** A modest hybrid could provide equity credit and rating flexibility, especially given the company’s capex-heavy renewable/infrastructure strategy. But the lack of prior hybrid issuance, still-strong equity base, improved earnings/cash flow, and higher hybrid cost argue against using the full S&P equity-credit capacity.

Therefore, the most appropriate recommendation is **limited use**, consistent with mild leverage optimization and moderate funding needs rather than a major capital-structure shift.

<answer>3.75%</answer>