Key Takeaways — Chapter 14: Market Risk and the Basel Framework in Practice

Core Definitions

Market risk is the risk of losses arising from adverse movements in market prices — interest rates, equity prices, exchange rates, commodity prices, credit spreads, and implied volatility.

Trading book positions are held for short-term trading and marked to market daily. Market risk capital (FRTB) applies to the trading book.

Banking book positions are held to maturity. Interest Rate Risk in the Banking Book (IRRBB) governs rate risk in the banking book — separately from market risk capital.


Basel Market Risk Capital: The Evolution

Regime Period Key Metric Confidence Holding Period
1996 Market Risk Amendment (IMA) 1996–2023 VaR 99% 10 days
FRTB — Standardized Approach (SA) 2025+ Sensitivity-based N/A Risk-class specific
FRTB — Internal Models Approach (IMA) 2025+ Expected Shortfall 97.5% Liquidity-horizon adjusted

Value at Risk (VaR): Three Approaches

Approach Method Key Assumption Strength Limitation
Historical Simulation Replay actual historical returns None (non-parametric) Captures actual fat tails Depends entirely on historical window
Parametric (Delta-Normal) σ × z × √t Normal distribution Fast; analytically tractable Fails for fat tails and options
Monte Carlo Random scenario generation Distribution specified Handles non-linearities Computationally intensive; model-dependent

VaR formula (parametric, 1-day): VaR = z₀.₉₉ × σ_portfolio = 2.326 × σ

10-day scaling: VaR₁₀ = VaR₁ × √10 (square root of time; assumes i.i.d. returns)


Expected Shortfall (ES) vs. VaR

Metric VaR (99%) ES (97.5%)
Definition Maximum loss not exceeded with 99% probability Average loss in worst 2.5% of scenarios
Tail information None — blind beyond the threshold Captures average magnitude of tail losses
Basel use Pre-FRTB IMA FRTB IMA
Regulatory rationale Established standard More risk-sensitive; addresses VaR's tail blindness

FRTB Key Concepts

P&L Attribution (PLA) Test: Each trading desk must demonstrate that its risk factor model explains actual trading P&L. Desks that fail PLA must use the SA — typically a higher capital charge.

Non-Modellable Risk Factors (NMRFs): Risk factors with insufficient market price observations. NMRF capital = stress scenario loss (not ES from history). Can significantly increase capital for illiquid positions.

Liquidity Horizons: Capital charges are scaled to the time needed to exit/hedge positions: - 10 days: liquid equity, G10 FX, G10 interest rates - 20 days: investment grade credit spreads, non-G10 FX - 40 days: high yield credit, investment grade corporates - 60 days: equity volatility, EM FX - 120 days: illiquid credit, physical commodity

FRTB Standardized Approach (SA): Sensitivity-based method using delta (linear risk), vega (volatility risk), and curvature (option non-linearity) inputs. More risk-sensitive than pre-FRTB SA.


VaR Backtesting: Basel Traffic Light System

Breaches in 250 days Zone Implication
0–4 Green Normal; no additional capital
5–9 Yellow Warning; potential capital multiplier increase
10+ Red Model concerns; regulatory attention; capital multiplier likely increased

IRRBB: Key Concepts

Economic Value of Equity (EVE): Net present value of all bank cash flows. EVE falls when rates rise (for a bank with more long-term assets than liabilities).

Net Interest Income (NII): Sensitivity of interest income to rate changes. A bank funded by variable-rate deposits and holding fixed-rate loans will see NII fall if rates rise.

Standard shocks (Basel IRRBB): Parallel ±200bp, short rates ±250bp, flattener, steepener. Supervisors compare EVE sensitivities across institutions.

IRRBB capital: Not a Pillar 1 charge — managed through Pillar 2 / ICAAP. PRA SS31/15 (UK) and ECB guidance require IRRBB capital commensurate with exposure.


Market Risk Technology Stack

Pricing Systems (Murex / Calypso / Bloomberg)
        ↓ Mark-to-market values + Greeks
Risk Calculation Engine (MSCI / Axioma / Numerix)
        ↓ VaR / ES / sensitivity measures
Risk Data Warehouse (Snowflake / cloud platform)
        ↓ Historical P&L / position data / backtesting
Regulatory Reporting Layer (FRR / FRTB platform)
        ↓ COREP C24–C32 templates + XBRL submission

COREP Market Risk Templates (Key)

Template Content
C 18.00 RWA overview — market risk line items
C 24.00 Market risk SA — total
C 25.00–28.00 Interest rate, equity, FX, commodity (SA)
C 31.00 FRTB SA — sensitivity-based method
C 32.00 FRTB IMA — ES by liquidity horizon and risk class

Common Practical Failure Modes

  1. Position data incompleteness: New instruments without risk factor mapping fall out of calculations
  2. Stale market data: Illiquid positions valued at outdated prices
  3. P&L attribution residuals: Risk engine P&L diverges from actual — FRTB PLA test failure
  4. Historical window gaps: Market data feed missing history needed for historical VaR
  5. NMRF identification failures: Non-modellable risk factors missed, undercharging capital

Practitioner Checklist: Market Risk Data Quality

  • [ ] Position completeness: all trading desk positions in risk engine daily
  • [ ] Market data coverage: all instrument risk factors have current and historical prices
  • [ ] Stale price monitoring: alert on positions unchanged for >2 days (for actively traded instruments)
  • [ ] P&L attribution: daily comparison of risk engine P&L to actual trading P&L; residuals < threshold
  • [ ] VaR backtesting: monthly count of breaches; report to risk committee quarterly
  • [ ] FRTB PLA test: calculated monthly for each IMA-approved desk
  • [ ] NMRF register: quarterly update of non-modellable risk factor list
  • [ ] IRRBB shocks: calculated monthly; reported to ALCO
  • [ ] COREP market risk templates: validated against risk engine outputs before submission