FRM Part II · FRM Exam Part II
Liquidity and Leverage: formula sheet
Key formulas
- Mid-price
- M = (Ask + Bid) ÷ 2
- Reference price for all spread measures.
- Quoted spread (absolute)
- Quoted spread = Ask − Bid
- Displayed cost of a round trip for a small trade.
- Relative quoted spread
- Relative spread = (Ask − Bid) ÷ M
- Allows comparison across assets with different prices.
- Effective spread
- Effective spread = 2 × D × (P − M), where D = +1 for a buy and −1 for a sell
- P is the trade price and M the mid-price at trade time. Divide by M for the relative form.
- Realized spread
- Realized spread = 2 × D × (P − M_later)
- M_later is the mid-price some time after the trade. Effective spread minus realized spread equals the price impact.
- Price impact
- Price impact = 2 × D × (M_later − M)
- Effective spread = realized spread + price impact.
- Liquidity cost in VaR (constant spread)
- LVaR = VaR + ½ × S × V
- S is the relative spread, V the position value. Assumes a known, constant spread and liquidation at the half-spread cost.
- Leverage
- Leverage = Total assets ÷ Equity
- Higher leverage means a given price fall wipes out more equity and forces larger sales.
- Haircut and funding
- Funding obtained = Collateral value × (1 − haircut)
- The equity you must supply per unit of asset equals the haircut. A rise in haircut forces deleveraging.
- Maximum position under margin
- Max position = Capital ÷ Margin rate
- If the margin rate rises, the maximum position falls, which drives the margin spiral.
- Funding gap
- Funding gap = Cash outflows − Cash inflows over a horizon
- A positive gap must be covered by buffers or new funding.
- Balance-sheet leverage (equity multiplier)
- Leverage = Total assets ÷ Equity
- Equity = assets − liabilities. A leverage of 10 means ₹1 of equity supports ₹10 of assets.
- Debt-to-equity
- D/E = Debt ÷ Equity = Leverage − 1
- Holds when all non-equity funding is counted as debt.
- Return on equity with leverage
- ROE = ROA × (Assets ÷ Equity) − (Assets − Equity) ÷ Equity × cost of debt
- Equivalent to ROE = r_A + (D/E) × (r_A − r_D). Leverage helps only if the asset return exceeds the cost of debt.
- Embedded leverage
- Embedded leverage = Exposure (notional or delta-adjusted) ÷ Funds invested
- For an option, delta-adjusted exposure = delta × underlying value × quantity. Funds invested = premium paid.
- Basel III leverage ratio
- Leverage ratio = Tier 1 capital ÷ Total exposure measure
- Non-risk-weighted. The exposure measure includes on-balance-sheet assets and specified off-balance-sheet items. Note it is the inverse direction of assets ÷ equity: higher is safer.
- Equity change from asset shock
- % change in equity ≈ Leverage × % change in assets
- Ignores funding cost and income. Wipe-out occurs when the asset fall ≥ 1 ÷ Leverage.
- Leverage multiple
- L = Assets ÷ Equity = 1 + Debt ÷ Equity
- Equity multiplier. Debt-to-equity is L − 1.
- Return on equity with leverage
- ROE = r_A + (r_A − r_D) × (D ÷ E) = L × r_A − (L − 1) × r_D
- r_A is the asset return, r_D the cost of debt. Both forms give the same value.
- Equity volatility
- σ_E = L × σ_A
- Valid when the borrowing cost is fixed (no uncertainty in r_D) and the leverage multiple is constant.
- Equity loss for an asset fall
- Equity return = −L × (asset fall) − (L − 1) × r_D
- This is the ROE formula with a negative r_A. Equity is exhausted when the asset fall ≥ 1 ÷ L (ignoring interest).
- Break-even asset return
- r_A = r_D
- Above it, leverage raises ROE. Below it, leverage lowers ROE.
- Basel III leverage ratio
- Leverage ratio = Tier 1 capital ÷ Total exposure measure
- Not risk-weighted. Basel III minimum is 3%.
- Equity VaR from asset VaR
- VaR on equity ≈ L × asset VaR (as % of equity)
- In currency terms the loss is the same on the assets; the percentage of equity is scaled by L.
- Haircut
- Haircut = (Collateral value − Cash lent) ÷ Collateral value
- Cash lent = Collateral value × (1 − haircut). Check whether the question quotes the haircut on collateral value.
- Equity funded by haircut
- Equity required = Asset value × haircut
- The rest of the position is financed by the lender.
- Maximum leverage
- Assets ÷ Equity = 1 ÷ haircut
- A 4% haircut allows 25 times; 10% allows 10 times.
- Margin call on haircut rise
- Extra equity = Asset value × (new haircut − old haircut)
- Assumes asset value is unchanged. If prices also fall, recompute with the new value.
- Forced sale to restore leverage
- Sale = Current assets − Equity ÷ haircut
- Equity is after any losses. Sale proceeds repay debt.
- Variation margin
- VM = Mark-to-market change of the position
- Paid by the party whose position lost value, usually daily.
- Exogenous spread cost (constant spread)
- Liquidity cost = 0.5 × S × P
- S is the relative spread = (ask − bid) ÷ mid. P is the position value. The 0.5 is because you give up half the spread to sell at the bid.
- LVaR with constant spread
- LVaR = VaR + 0.5 × S × P
- VaR is measured at the mid-price. Both amounts are in the same currency and for the same position.
- LVaR with stochastic spread
- LVaR = VaR + 0.5 × (μS + k × σS) × P
- μS is the mean relative spread, σS its standard deviation, and k the confidence multiplier (for example 2.33 at 99% if the spread is assumed normal).
- Relative spread
- S = (Ask − Bid) ÷ Mid, where Mid = (Ask + Bid) ÷ 2
- Use the relative form. An absolute spread must be divided by the mid-price first.
- Square-root-of-time scaling for horizon
- VaR(T days) = VaR(1 day) × √T
- Valid under independent, identically distributed returns with zero mean. Use it when the liquidation takes T days.
- Liquidation horizon trade-off
- Total cost = market risk over horizon + market impact cost
- A longer horizon raises price risk and lowers impact. The optimal horizon minimises the total. This is a concept to recall, not a formula to compute.
- Leverage ratio
- Leverage = Total assets ÷ Equity
- Equity multiplier. Leverage of 20 means equity is 5% of assets.
- Equity change from asset return
- Return on equity ≈ Leverage × Asset return (ignoring funding cost)
- A 2% asset fall at leverage 20 is roughly a 40% equity fall.
- Haircut
- Haircut = 1 − (Loan ÷ Collateral market value)
- Higher haircut means less borrowing against the same collateral.
- Maximum assets funded with a haircut
- Assets = Equity ÷ Haircut
- A 5% haircut permits leverage of 20. A 10% haircut permits only 10.
- Sales needed to restore a target leverage
- Required asset reduction = Current assets − (Equity × Target leverage)
- Assumes sale proceeds repay debt and equity stays fixed after the loss.
- Spiral sequence
- Shock → losses → lower equity or higher haircuts → forced sales → lower prices → more losses
- Know the loop and where policy can break it.
Quick revision
- Market liquidity is the ability to trade quickly at low cost without moving the price.
- Funding liquidity is the ability to meet cash and collateral demands when due.
- Quoted spread = ask − bid; relative spread = (ask − bid) ÷ mid-price.
- Cost of selling at the bid is half the spread per unit relative to mid.
- Leverage ratio = total assets ÷ equity; debt-to-equity is a different ratio.
- Leverage magnifies gains and losses; volatility of equity returns rises roughly in proportion to leverage.
- Levered return = asset return × leverage − borrowing rate × (leverage − 1).
- A haircut is the part of collateral value that cannot be borrowed against; the borrower funds it with own capital.
- Higher haircuts and margin demands in stress force deleveraging and asset sales.
- LVaR adds a liquidity cost, often half the spread times position value, to ordinary VaR.
- Funding and market liquidity reinforce each other in a liquidity spiral.
- Embedded leverage in derivatives can be high even when balance sheet leverage looks low.
Common mistakes
- Treating the effective spread as the same as the quoted spread. Fix: Quoted comes from displayed bid and ask. Effective comes from the actual trade price against mid, so it can be smaller (price improvement) or larger (walking the book).
- Forgetting to multiply by 2 in effective and realized spreads. Fix: Effective and realized spreads are defined as twice the signed deviation, so they are comparable to a full quoted spread.
- Treating funding liquidity and market liquidity as the same thing. Fix: Funding is about meeting obligations with cash or collateral. Market is about selling an asset near fair value.
- Confusing the loss spiral with the margin spiral. Fix: Loss spiral starts with losses reducing capital. Margin spiral starts with higher margins or haircuts due to higher volatility or uncertainty.
- Confusing debt-to-equity with assets-to-equity. Fix: Remember assets ÷ equity = 1 + D/E. Read which one the question asks for.
- Using notional instead of delta-adjusted exposure for options. Fix: Embedded leverage of an option uses delta × underlying ÷ premium unless the question defines it otherwise. Notional overstates the real exposure.
- Using the debt-to-equity ratio instead of the leverage multiple to scale volatility. Fix: Scale by Assets ÷ Equity. Debt-to-equity is one less than that.
- Charging the cost of debt on the whole asset base. Fix: Interest is paid only on the borrowed amount, which is (L − 1) times equity.
- Treating the haircut as the interest rate or the lender's fee. Fix: The haircut is the collateral cushion. The repo rate is the price of the cash.
- Swapping initial and variation margin. Fix: Initial margin is a buffer for future moves and default close-out. Variation margin settles current mark-to-market gains and losses.
Exam tips
- Always compute the mid-price first. Most spread questions are one step after that.
- Watch the word half. Many answer options differ only by a factor of 2.
- Know the link: effective spread = realized spread + price impact. Questions often give two and ask for the third.
- For concept questions, match the term to the dimension: spread = tightness, volume at quote = depth, speed of recovery = resilience.
- Remember the LVaR assumption of a constant spread. If spread varies, the basic add-on understates the risk.
- Read the first trigger in the vignette: losses mean loss spiral, margin or haircut increases mean margin spiral.
- Expect questions linking short-term wholesale funding and maturity mismatch to funding liquidity risk.
- Watch for answers claiming the two liquidity risks are independent. They are wrong in stress.