Market Impact

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Written By
Contributor Image
Written By
Dan Buckley
Dan Buckley is an US-based trader, consultant, and part-time writer with a background in macroeconomics and mathematical finance. He trades and writes about a variety of asset classes, including equities, fixed income, commodities, currencies, and interest rates. As a writer, his goal is to explain trading and finance concepts in levels of detail that could appeal to a range of audiences, from novice traders to those with more experienced backgrounds.

Market impact is a concept in financial markets, referring to the effect a market participant has when buying or selling an asset.

It is an essential consideration for large investors, such as financial institutions, as it can significantly influence investment decisions and overall profitability.

This article will explore the nuances of market impact, its relationship with market liquidity, and the strategies institutions can employ to manage it effectively.


Key Takeaways – Market Impact

  • Market impact is the effect that buying or selling an asset has on the market and is an important consideration for large investors. It can significantly influence trading and investment decisions and overall profitability.
  • Market impact is closely related to market liquidity, which represents the ease of buying or selling an asset without causing significant price changes.
  • Highly liquid markets can accommodate large transactions without price fluctuations, while less liquid markets experience notable price changes even with smaller transactions.
  • Managing market impact involves strategies such as limiting the pace of activity, breaking down large orders into smaller parts, and using algorithmic trading. These approaches help minimize price disruptions and optimize investment returns.


Market Impact and Market Liquidity: A Symbiotic Relationship

Market impact is closely related to market liquidity, with the two terms often being used synonymously.

Liquidity represents the ease with which an asset can be bought or sold without causing a significant change in its price.

When a market is highly liquid, it can accommodate large transactions without experiencing substantial price fluctuations.

Conversely, in less liquid markets, even smaller transactions can lead to notable price changes.

The degree of market impact hinges on the size of the transaction relative to the asset’s turnover.

In cases where the transaction amount is significant, the market impact can amount to several percentage points, necessitating careful assessment alongside other transaction costs.

The bigger the transaction sizes, the more transaction costs tend to go up in a non-linear way.


Causes of Market Impact

There are two primary reasons for market impact:

Counterparty Incentives

Prices may need to shift to encourage other investors to buy or sell assets, acting as counterparties in the transaction.

When a large investor is buying, the price moves upward as it eats up various sell orders, and when selling, the price moves downward.

For example, let’s say a trader wants to sell 100,000 shares of a stock trading at $50.00 per share.

And let’s say there are only 1,000 shares of stock waiting to be bought at $50.00, 1,000 shares at $49.99, 1,000 at $49.98, etc.

To execute that order, it would push the price all the way down to $49.01 in order to execute it all.

If more buyers come in, it would be higher, if buyers leave while the process is going on, the price will go lower.

Positioning by Professional Investors

Professional traders and investors, aware of a large investor’s activity, may position themselves to profit from the anticipated price movement.

Some financial intermediaries possess such low transaction costs that they can profit from even minor price fluctuations that may be inconsequential to most investors.


Managing Market Impact

To effectively manage market impact, financial institutions need to adopt certain strategies:

Limiting the Pace of Activity

By keeping their activity below a certain threshold, such as staying below 10% of the daily turnover as a crude rule of thumb, institutions can avoid disrupting asset prices.

This helps maintain price stability and reduces the likelihood of incurring additional costs due to market impact.

Breaking Down Large Orders

Dividing substantial transactions into smaller parts can help minimize market impact.

This approach allows institutions to execute orders over a more extended period without causing significant price fluctuations.

Utilizing Algorithmic Trading

Advanced algorithmic trading strategies can help institutions execute large orders intelligently and discretely.

These algorithms can analyze market conditions and execute trades at optimal times to minimize the impact of large trades.

VWAP indicators are a popular example.



Market impact is an important aspect of trading activity and financial markets, significantly influencing the decisions of large investors like financial institutions (but not so much smaller individual investors).

It is intrinsically tied to market liquidity, and its management is essential for maximizing investment returns.

By employing strategic approaches such as limiting the pace of activity, breaking down large orders, and using algorithmic trading, institutions can effectively manage market impact and optimize their overall performance.