What Is the Capital Stack?
The capital stack is a visual and legal ordering of every dollar financing an asset, arranged by payment priority. In a typical stack, senior debt sits at the top, subordinated or mezzanine debt sits in the middle, preferred equity comes next, and common equity sits at the bottom. Cash flows are distributed from the top down, while losses are absorbed from the bottom up.
The term is used most heavily in real estate and leveraged buyouts, but the logic applies to any company. It is closely related to capital structure — the difference is mostly emphasis. Capital structure usually describes the overall debt-versus-equity mix of a corporation, while the capital stack describes the specific layers, their ranking, and their negotiated terms within a single deal.
How the Layers Work
Each layer prices its position. Senior lenders take the least risk, so they accept the lowest return — often a floating rate such as SOFR plus 200 to 400 basis points, secured by first liens on the assets. Mezzanine and subordinated lenders sit behind them and typically demand roughly 10% to 13%, sometimes with warrants attached. Preferred equity earns a fixed dividend ahead of common holders, and common equity targets the highest returns, frequently 15% to 25% IRRs in sponsor-backed deals.
Consider a $100 million property financed with $60 million of senior debt, $15 million of mezzanine debt, and $25 million of equity. If the property later sells for $80 million, the senior lender is repaid in full, the mezzanine lender recovers its $15 million, and equity receives only $5 million — an 80% loss. The stack turned a 20% decline in asset value into a wipeout-level outcome for the bottom layer.
Why the Capital Stack Matters
Position in the stack drives everything about an investment: expected return, downside protection, control rights, and covenant protections. Investors reaching for higher yield by moving down the stack must understand they are also moving toward first-loss exposure. Conversely, sponsors engineer returns by layering cheaper debt above their equity, which is the entire premise of the leveraged buyout model.
In IB and PE interviews, candidates are routinely asked to rank instruments by risk or to walk through who gets paid what in a downside scenario. Fluency with the capital stack shows you understand how deals are actually financed rather than just how they are valued, and it is the foundation for more advanced topics like intercreditor dynamics and structural subordination.
