Based on the financial data and the company's historical capital structure, here is the assessment of whether BOUYGUES should issue hybrid bonds over the next 18 months:

1. **Historical Precedent and Capital Structure**: BOUYGUES has never issued hybrid bonds in the past ("First year of hybrid bond issuance: never"). As noted in the guidelines, an entity's historical absence of hybrid bond issuance is a strong and reliable signal that it prefers to rely on other funding levers. Management has not utilized hybrids even recently despite executing a massive transformational acquisition (the acquisition of Equans for over €6 billion, driving 2022 net debt to €7.44 billion). They chose to finance this entirely with available cash and new senior debt issuance.

2. **Leverage and Rating Metrics**: While BOUYGUES' Moody's adjusted leverage trend deteriorated due to the Equans acquisition (S&P Net Debt / EBITDA stands at 3.26x), its FFO to Net Debt metric remains adequate at 24.46%. The group inherently benefits from a strong "A" range rating profile (A-/A3) driven by its substantial scale, business diversity (Telecoms, Construction, Media), and predictable cash flows. It has sufficient headroom at its current rating to absorb the acquisition leverage without depending on equity-like instruments to aggressively defend the rating.

3. **Cost of Capital**: Current market conditions point to an elevated yield environment. As a highly rated corporate, BOUYGUES can issue regular senior unsecured debt at attractive rates compared to hybrids, which typically bear a subordination premium. Introducing a hybrid instrument would needlessly increase the group's overall cost of debt while adding complexity to a capital structure that currently does not include any hybrid debt.

Given these factors—most notably the complete lack of historical hybrid issuance, a solid investment-grade rating profile, and a capital structure that adequately supports its strategic growth without the need for subordination—BOUYGUES has no compelling rationale to introduce hybrid bonds. 

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