In a securitization structure, the equity tranche is the most subordinate. It is often referred to as the 'first-loss' tranche as it is the first to absorb losses and the last to receive payments. Equity tranches typically do not receive a fixed coupon payment. Instead, they are entitled to the residual cash flows after all other obligations of the Special Purpose Entity (SPE) have been satisfied. This means that the equity tranche is fully exposed to defaults in the collateral pool. If the underlying assets perform well, the equity tranche can provide high returns. However, if the assets perform poorly, the equity tranche can suffer significant losses.

Choice B is incorrect. Junior debt tranches are not the last to receive payments in a securitization structure. They are subordinated to senior debt tranches, meaning they bear more risk than senior tranches but less than equity tranches. They do receive fixed coupon payments, unlike equity tranches.

Choice C is incorrect. Senior debt is the most secure tranche in a securitization structure and has priority over other tranches when it comes to payment of principal and interest. It does not bear the full brunt of defaults as described in the question; that characteristic belongs to the equity tranche.

Choice D is incorrect. Capital stack refers to the total capital invested in a project, including all types of financing - from senior debt to junior debt and equity. It's not a specific tranche that bears default risk or receives residual cash flows after all other obligations have been met.

Things to Remember

• The equity tranche is also known as the "first-loss" tranche, meaning it is the first to absorb losses in the event of default within the securitized portfolio.
• Equity tranches get completely wiped out once losses reach a certain threshold, typically a certain percentage of the notional value, which emphasizes the high risk and potential for total loss within this tranche.