To determine the extent to which Verbund AG should rely on hybrid bonds in its capital structure, we must evaluate the company's financial position, market conditions, and debt-servicing capacity.

1. **Financial Strength**: Verbund AG has demonstrated strong financial performance. In 2022, Revenue increased significantly to 10.35 billion EUR (from 4.78 billion EUR in 2021). EBITDA also showed robust growth, reaching 3.16 billion EUR in 2022 compared to 1.58 billion EUR in 2021. Profit for the period more than doubled to 1.95 billion EUR.
2. **Current Leverage and Liquidity**: The company maintains a healthy balance sheet with 8.32 billion EUR in total equity as of the end of 2022. While debt increased (Noncurrent financial liabilities rose from 1.83 billion EUR to 2.84 billion EUR), the company's operating cash flow is exceptionally strong (2.02 billion EUR in 2022), providing ample coverage for interest expenses.
3. **Market Environment**: The provided market data (Swap Curves 5Y/7Y/10Y) shows a significant increase in interest rates from 2021 to 2022 (e.g., the 10Y swap rate rose from 0.053% to 1.927%). Hybrid bonds are typically more expensive than senior debt due to their subordinated nature and accounting treatment as equity/debt hybrids. 
4. **Strategic Capital Allocation**: Given Verbund's strong cash flow and current ability to issue senior debt at favorable rates relative to the cost of hybrids, relying heavily on hybrid instruments (which are expensive and dilutive to credit quality) is inefficient. A balanced approach suggests a low reliance on hybrid debt, as the firm does not need to aggressively "boost" its equity base to maintain credit ratings or capital adequacy.

Considering the company's robust profitability, high cash generation, and the increased cost of debt in the current interest rate environment, a minimal reliance on hybrid bonds is appropriate to avoid unnecessary financing costs.

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