Quant with Vahab
Quant Systems Lab · Control Systems for Quantitative Finance

Margin and Leverage

Leverage amplifies gains and losses; margin is the collateral mechanism that enforces survival constraints.

Explanation

Leverage increases exposure relative to equity; small moves can wipe out capital.

Margin calls force deleveraging when losses occur or requirements rise.

In stress, margin and liquidity interact: forced selling can create feedback loops.


leveragemarginrisk management
Interactive visualisation

Leverage scales your exposure relative to equity. A given price move hits leveraged equity harder, and margin requirements enforce a minimum equity ratio relative to exposure.

Equity before and after a price shock, with margin requirement band0Initial equity100Equity after shock40.0Margin requirement (30% of exposure)
Numbers
Initial equity ≈ 100
Exposure ≈ 300
Borrowed ≈ 200
Equity after shock ≈ 40.0 (40.0% of start)
Equity ratio after ≈ 13.3% of exposure
Status: Margin call region
Interpretation

For a fixed price shock, higher leverage makes equity more volatile: equity moves in percentage terms roughly by leverage × shock. Once the equity ratio drops below the margin requirement, the position must be reduced or capital added.

Margin is a survival constraint: it enforces a floor on equity relative to exposure. In stress, falling prices, rising margins and poor liquidity can combine into forced deleveraging and feedback loops.