How do netting agreements reduce counterparty exposure and how is netting set exposure calculated?

Netting is one of the most important risk mitigation tools in OTC derivatives. A netting set is a group of trades with the same counterparty that are governed by a single master netting agreement (typically an ISDA Master Agreement). If the counterparty defaults, you can offset all positive MTM trades against negative MTM trades within the set, rather than paying on losing trades while losing on winning ones.

Without Netting (Gross Exposure)

Suppose Ashton Capital has 4 trades with Counterparty X:

Gross Positive Exposure = $8M + $5M = $13 million (you'd lose this if X defaults and you must still pay on negative trades)

With Netting (Net Exposure)

Net Exposure = max(0, sum of all MTMs) = max(0, $8M − $3M + $5M − $6M) = max(0, $4M) = $4 million

Netting reduced exposure from $13M to $4M — a 69% reduction.

Netting Benefit Ratio

NBR = Net Exposure / Gross Exposure = $4M / $13M = 0.31

A lower NBR means more netting benefit. The NBR depends on:

• Number of trades (more trades = more netting)
• Correlation between trade values (lower correlation = more benefit)
• Directional bias (all-positive portfolio = no netting benefit)

Expected Exposure Under Netting

For regulatory and CVA calculations, you need the expected future exposure profile. Under netting:

EE_net(t) = E[max(0, sum of V_i(t))]

This is computed via Monte Carlo simulation:

1. Simulate all risk factors (rates, FX, credit spreads) forward to each time step.
2. Revalue every trade in the netting set.
3. Sum all MTM values.
4. Take max(0, sum).
5. Average across scenarios.

The netting benefit grows with portfolio diversity. If all trades are receive-fixed interest rate swaps, they move together and netting helps little. If the portfolio includes offsetting FX forwards and IR swaps, the benefit is substantial.

Exam Tip: Know the difference between bilateral netting (two parties offset directly) and multilateral netting (a CCP nets across multiple participants). CCP netting is even more powerful but introduces CCP credit risk.

Practice more counterparty risk problems in our FRM Part II question bank.