Systemic Risk and Contagion

Connectivity, Feedback, and the Propagation of Stress in Financial Markets

Financial markets are often evaluated through the lens of individual assets, institutions, or strategies. Risk is assessed locally, exposures are measured at the portfolio level, and outcomes are interpreted in terms of isolated performance.

However, this perspective can obscure a critical dimension of financial systems. Markets are interconnected.

Within these interconnected structures, risks do not remain contained. They propagate. A disturbance in one part of the system can spread through channels of exposure, behaviour, and liquidity, affecting components far removed from the original source. This phenomenon is captured by the concepts of systemic risk and contagion.

Defining Systemic Risk

Systemic risk refers to the possibility that disturbances within the financial system lead to widespread disruption. Unlike idiosyncratic risk, which affects individual components, systemic risk impacts the system as a whole.

It arises when:

• institutions or assets are interconnected

• exposures are concentrated

• feedback mechanisms amplify shocks

Under these conditions, the failure or distress of one component can trigger cascading effects. The system becomes vulnerable not only to the size of shocks, but to the structure through which they propagate.

The Nature of Contagion

Contagion describes the process by which risk spreads. It is not limited to direct exposure.

While financial linkages such as counterparty relationships and shared holdings provide clear transmission channels, contagion also operates through:

• behavioural responses

• changes in expectations

• liquidity dynamics

Participants observing stress may adjust their behaviour, leading to:

• reduced risk-taking

• asset sales

• withdrawal of liquidity

These actions can transmit stress even in the absence of direct connections.

Networks and Transmission Channels

The network structure of financial markets plays a central role in systemic risk. Connections between nodes; whether assets, institutions, or strategies; determine how shocks propagate.

Highly connected nodes can act as hubs, namely:

• stress affecting a central node may influence a large portion of the system

• disruptions can spread rapidly through multiple pathways

At the same time, clusters of tightly connected components may amplify local shocks before transmitting them outward. Understanding these structures is essential for analysing contagion.

Feedback and Amplification

Systemic risk is characterised by feedback.

Initial shocks can be amplified through mechanisms such as:

• forced deleveraging

• margin calls

• liquidity constraints

As prices decline, participants may be required to reduce exposure. This can lead to further selling, driving prices lower and triggering additional adjustments. These feedback loops can transform moderate disturbances into large-scale disruptions. The system becomes non-linear. As, outcomes are not proportional to initial shocks.

Liquidity and Market Functioning

Liquidity plays a central role in systemic dynamics. Under normal conditions, markets facilitate the transfer of risk through active trading.

During periods of stress, liquidity may deteriorate, for example:

• bid–ask spreads widen

• depth decreases

• execution becomes uncertain

This reduces the system’s ability to absorb shocks. Participants attempting to adjust positions may encounter constraints, leading to further instability. Liquidity, therefore, acts as both a stabilising and destabilising force, depending on conditions.

Synchronisation and Correlation

Systemic events are often associated with increased synchronisation. Assets that typically behave independently may begin to move together.

This convergence of behaviour can result from:

• shared exposure to common factors

• coordinated responses to stress

• shifts in risk perception

As correlation rises, diversification benefits diminish. Portfolios that appeared well balanced may experience simultaneous losses across positions. This dynamic reinforces the impact of systemic risk.

Information and Perception

Contagion is influenced by information and perception. Market participants interpret signals, adjust expectations, and act accordingly.

Uncertainty can amplify these effects, namely:

• incomplete information may lead to precautionary behaviour

• rumours or partial data can trigger responses

• perception of risk may exceed objective exposure

This introduces a psychological dimension to contagion. Stress can spread not only through direct connections, but through shared interpretation of events.

Historical Perspective

Episodes of systemic risk illustrate these dynamics.

While each event is shaped by specific conditions, common patterns emerge:

• initial disturbance

• transmission through interconnected structures

• amplification via feedback mechanisms

• widespread impact across the system

These patterns highlight the importance of structure and interaction in determining outcomes.

The MorMag Perspective

At MorMag, systemic risk is understood as an emergent property of interconnected systems.

The framework integrates:

• network analysis to identify structural relationships

• probabilistic modelling to assess uncertainty

• behavioural insights to interpret participant response

This approach emphasises that:

• risk is not confined to individual components

• interactions shape outcomes

• system-level dynamics must be considered

Quantitative tools provide structure, but interpretation focuses on how shocks may propagate and evolve.

From Local Risk to Systemic Understanding

Traditional risk analysis often focuses on local exposures. Systemic risk requires a broader perspective.

It involves understanding:

• how components are connected

• how shocks travel through the system

• how feedback mechanisms amplify effects

This shift from local to systemic thinking is essential in complex financial environments.

Conclusion

Systemic risk and contagion reflect the interconnected nature of financial markets.

They describe how disturbances propagate, how feedback amplifies outcomes, and how local events can become global disruptions. Understanding these dynamics requires moving beyond isolated analysis toward a network-based perspective that incorporates structure, behaviour, and interaction.

At MorMag, this perspective informs a disciplined approach to risk management, in which the focus extends beyond individual positions to the system as a whole.

In financial markets, risk is not only what is held. It is how everything is connected. Recognising this is essential for navigating complexity with clarity and resilience.