{"concept":{"id":84,"slug":"position-sizing","term":"Position sizing","shortDefinition":"The criterion for deciding how much weight a position should have in a portfolio based on how much concentration risk it introduces and how correlated it is with the rest -- a tool for controlling its contribution to risk, not a universal formula.","longDefinition":"Position sizing is the criterion for deciding how much weight a specific position should have within a portfolio, inside the asset allocation already decided in Module 1. It rests on two factors: the concentration risk a position introduces -- the greater its weight, the greater the part of the portfolio exposed to whatever happens specifically to that position -- and its correlation with the rest of the portfolio -- a position highly correlated with the others contributes more to overall risk than one with low correlation, even with the same nominal weight. It's a tool for controlling how much a specific position contributes to a portfolio's risk, not a universal formula or a fixed percentage that automatically determines how much anyone should invest in any position."},"relations":{"requirement":[],"contrast":[],"related":[{"concept":{"id":82,"slug":"concentration-risk","term":"Concentration risk","shortDefinition":"The risk that arises from having too much capital in too few positions, sectors, or geographic regions, such that a single event can affect a disproportionate part of the portfolio -- reduced by diversification.","longDefinition":"Concentration risk is the risk that arises from having too much capital invested in too few positions, sectors, or geographic regions, such that a single event can affect a disproportionate part of the portfolio. It isn't a different kind of uncertainty from risk, already covered in Level 1 -- it's a specific form of risk that depends on how the portfolio as a whole is structured, not on the uncertainty of each asset considered separately: a portfolio can have high concentration risk even if no individual position, considered on its own, is especially risky. Diversification, already covered in Module 2, is precisely the practice that reduces this risk."}},{"concept":{"id":83,"slug":"correlation","term":"Correlation","shortDefinition":"The tendency of two assets to move in the same direction, in opposite directions, or independently in response to the same events -- the real mechanism through which diversifying reduces a portfolio's risk.","longDefinition":"Correlation measures the tendency of two assets to move in the same direction, in opposite directions, or independently in response to the same events. Two highly correlated assets tend to rise and fall together; two assets with low or negative correlation don't move similarly, or even move in opposite directions. It's the real mechanism behind the benefit of diversifying, already covered in general terms in Module 2: combining assets with low correlation to each other reduces the portfolio's overall risk more than combining highly correlated assets would. It shouldn't be confused with volatility, already covered in Level 1: volatility measures how much a single asset moves on its own, while correlation measures how two assets move relative to each other -- an asset can be very volatile and, at the same time, have low correlation with another."}},{"concept":{"id":79,"slug":"asset-allocation","term":"Asset allocation","shortDefinition":"The decision of what percentage of a portfolio goes to each asset class -- the central decision in building a portfolio, distinct from choosing which specific asset to buy within each class.","longDefinition":"Asset allocation is the decision of what percentage of a portfolio goes to each asset class -- stocks, bonds, ETFs, investment funds, commodities, currencies, all already covered in Level 1. It isn't choosing which specific stock or fund to buy within each class -- that's a later decision. According to numerous portfolio management studies, it's the decision that most influences a portfolio's long-term result, because different asset classes behave differently in response to the same events: combining them in the right proportions is the main lever for adjusting the risk and expected return of an entire portfolio, both already covered in Level 1. The right allocation depends on the investor's risk profile, their time horizon, and their liquidity needs."}}],"calculatedBy":[]},"curricularPosition":[{"id":76,"moduleId":27,"slug":"how-is-a-position-sized","title":"How is a position sized?","summary":"You understand what criterion guides how much weight a position should have in a portfolio, without it being a universal formula.","bodyMarkdown":"## Objectives\n\nBy the end of this lesson you understand what criterion guides how much weight a position should have in a portfolio, without it being a universal formula.\n\n## Content\n\nThe two previous lessons introduced concentration risk and correlation between assets. This lesson closes the module with the question both leave open: how much specific weight should a position have within a portfolio?\n\nPosition sizing is the criterion for deciding how much weight a specific position should have, within the asset allocation already decided in Module 1. It's a tool for controlling how much that position contributes to the portfolio's risk -- not a universal formula or a fixed percentage that automatically determines how much anyone should invest in any position.\n\nThat criterion rests on the two factors introduced in the previous lessons. The first is the concentration risk the position itself introduces: the greater its weight within the portfolio, the greater the part of the total exposed to whatever happens specifically to that position. The second is its correlation with the rest of the portfolio: a position highly correlated with the others contributes more to overall risk than a low-correlation position, even with the same nominal weight -- because what affects one tends to also affect those correlated with it, while a poorly correlated position cushions part of that effect.\n\nThere's no single formula or universal percentage valid for any investor or any position. What does exist is a criterion: the greater the concentration risk a position introduces, or the more correlated it is with the rest of the portfolio, the smaller its relative weight should generally be -- and conversely, a position with lower concentration risk and lower correlation with the rest can generally sustain a larger relative weight without raising the overall risk as much.\n\nThis completes the module: concentration risk, correlation between assets, and the position-sizing criterion together give you the tools to manage risk within an already diversified portfolio.\n\n## Example\n\nTwo positions of the same nominal weight within a portfolio don't contribute equally to its risk if one is highly correlated with the rest of the portfolio and the other isn't: the first amplifies whatever is already happening to the whole when it's affected, while the second cushions part of that effect by not moving the same way.\n\n## Common mistakes\n\n- Thinking there's a fixed percentage valid for any position in any portfolio, without accounting for the concentration risk or correlation that specific position introduces.\n- Thinking two positions of the same nominal size contribute equally to the portfolio's risk, without considering their correlation with the rest.\n\n## Summary\n\nPosition sizing is the criterion for deciding how much weight a position should have, resting on the concentration risk it introduces and its correlation with the rest of the portfolio -- a tool for controlling its contribution to risk, not a universal formula or a fixed percentage valid for every case.\n\n## Self-check\n\nWhy are concentration risk and correlation the two factors that guide how much weight a position should have?\n\nWhy isn't there a universal percentage valid for sizing any position in any portfolio?","bodyHtml":"<h2>Objectives</h2>\n<p>By the end of this lesson you understand what criterion guides how much weight a position should have in a portfolio, without it being a universal formula.</p>\n<h2>Content</h2>\n<p>The two previous lessons introduced concentration risk and correlation between assets. This lesson closes the module with the question both leave open: how much specific weight should a position have within a portfolio?</p>\n<p>Position sizing is the criterion for deciding how much weight a specific position should have, within the asset allocation already decided in Module 1. It's a tool for controlling how much that position contributes to the portfolio's risk -- not a universal formula or a fixed percentage that automatically determines how much anyone should invest in any position.</p>\n<p>That criterion rests on the two factors introduced in the previous lessons. The first is the concentration risk the position itself introduces: the greater its weight within the portfolio, the greater the part of the total exposed to whatever happens specifically to that position. The second is its correlation with the rest of the portfolio: a position highly correlated with the others contributes more to overall risk than a low-correlation position, even with the same nominal weight -- because what affects one tends to also affect those correlated with it, while a poorly correlated position cushions part of that effect.</p>\n<p>There's no single formula or universal percentage valid for any investor or any position. What does exist is a criterion: the greater the concentration risk a position introduces, or the more correlated it is with the rest of the portfolio, the smaller its relative weight should generally be -- and conversely, a position with lower concentration risk and lower correlation with the rest can generally sustain a larger relative weight without raising the overall risk as much.</p>\n<p>This completes the module: concentration risk, correlation between assets, and the position-sizing criterion together give you the tools to manage risk within an already diversified portfolio.</p>\n<h2>Example</h2>\n<p>Two positions of the same nominal weight within a portfolio don't contribute equally to its risk if one is highly correlated with the rest of the portfolio and the other isn't: the first amplifies whatever is already happening to the whole when it's affected, while the second cushions part of that effect by not moving the same way.</p>\n<h2>Common mistakes</h2>\n<ul><li>Thinking there's a fixed percentage valid for any position in any portfolio, without accounting for the concentration risk or correlation that specific position introduces.</li><li>Thinking two positions of the same nominal size contribute equally to the portfolio's risk, without considering their correlation with the rest.</li></ul>\n<h2>Summary</h2>\n<p>Position sizing is the criterion for deciding how much weight a position should have, resting on the concentration risk it introduces and its correlation with the rest of the portfolio -- a tool for controlling its contribution to risk, not a universal formula or a fixed percentage valid for every case.</p>\n<h2>Self-check</h2>\n<p>Why are concentration risk and correlation the two factors that guide how much weight a position should have?</p>\n<p>Why isn't there a universal percentage valid for sizing any position in any portfolio?</p>","sortOrder":3,"readingMinutes":7,"difficulty":"Intermedio","url":"/en/academy/portfolio-management/risk-management/how-is-a-position-sized"},{"id":83,"moduleId":30,"slug":"how-do-you-build-an-investment-portfolio-step-by-step","title":"How do you build an investment portfolio, step by step?","summary":"You know how to combine the asset allocation, diversification, and risk management already covered in this level to build a real investment portfolio, step by step.","bodyMarkdown":"## Objectives\n\nBy the end of this lesson you know how to combine the asset allocation, diversification, and risk management already covered in this level to build a real investment portfolio, step by step.\n\n## Content\n\nThis level's five previous modules introduced, one by one, the criteria that make up a coherent portfolio: asset allocation based on risk profile and time horizon, diversification, managing concentration risk and correlation, rebalancing, and investor taxation. This lesson doesn't add any new criterion -- it brings together the ones already covered into a practical sequence.\n\nThe starting point is always the same: asset allocation, already covered in Module 1, decided from the investor's risk profile and time horizon. That allocation sets, in general terms, what proportion of the portfolio would correspond to each asset class -- stocks, bonds, ETFs, investment funds, commodities, or currencies, all already covered in Level 1 -- before choosing any specific instrument.\n\nOnce the allocation is set, the next step is diversifying within each asset class and across them, already covered in Module 2: combining assets that don't all behave the same way reduces the portfolio's risk without proportionally reducing expected return. Diversifying isn't simply adding up different instruments -- it's watching, as Module 3 showed, that no position concentrates a disproportionate risk, taking into account how the chosen positions relate to each other.\n\nSizing each position, also covered in Module 3, is what translates the allocation and diversification into concrete numbers: how much weight each position gets within the portfolio, consistent with its contribution to overall risk, not just with the investor's conviction in that specific idea.\n\nFinally, building a portfolio doesn't end at the moment of purchase. The tax cost of trades -- already covered in Module 5 -- and the future need to rebalance -- already covered in Module 4 -- are part of the criteria from the start, not an afterthought: a well-built portfolio anticipates that it will need to be reviewed over time, a topic the next lesson develops.\n\n## Example\n\nAn investor with a long time horizon and a risk profile that tolerates swings decides, based on their asset allocation, to put most of the portfolio into stocks and a smaller part into bonds. Within the stock portion, they diversify across several companies and sectors instead of concentrating the investment in just one; within the bond portion, they do the same across several issuers. Position weights have been set accounting for their contribution to concentration risk and how they relate to the rest of the positions.\n\n## Common mistakes\n\n- Choosing the specific instruments first and deciding the asset allocation afterward, instead of the other way around -- the allocation should precede the selection, not follow it.\n- Confusing \"diversifying\" with \"accumulating many different instruments\" without watching the real correlation between them.\n- Building the portfolio without considering from the start that it will have a tax cost and will need rebalancing -- treating both as a later surprise instead of a design criterion.\n\n## Summary\n\nBuilding a real portfolio means applying, in sequence, the criteria already covered in this level: asset allocation based on risk profile and time horizon, diversification within and across asset classes, sizing each position based on its contribution to overall risk, and anticipating the tax cost and the future need to rebalance.\n\n## Self-check\n\nWhy should asset allocation be decided before choosing the specific instruments that will make up the portfolio?\n\nWhy isn't diversifying the same as simply accumulating different instruments?","bodyHtml":"<h2>Objectives</h2>\n<p>By the end of this lesson you know how to combine the asset allocation, diversification, and risk management already covered in this level to build a real investment portfolio, step by step.</p>\n<h2>Content</h2>\n<p>This level's five previous modules introduced, one by one, the criteria that make up a coherent portfolio: asset allocation based on risk profile and time horizon, diversification, managing concentration risk and correlation, rebalancing, and investor taxation. This lesson doesn't add any new criterion -- it brings together the ones already covered into a practical sequence.</p>\n<p>The starting point is always the same: asset allocation, already covered in Module 1, decided from the investor's risk profile and time horizon. That allocation sets, in general terms, what proportion of the portfolio would correspond to each asset class -- stocks, bonds, ETFs, investment funds, commodities, or currencies, all already covered in Level 1 -- before choosing any specific instrument.</p>\n<p>Once the allocation is set, the next step is diversifying within each asset class and across them, already covered in Module 2: combining assets that don't all behave the same way reduces the portfolio's risk without proportionally reducing expected return. Diversifying isn't simply adding up different instruments -- it's watching, as Module 3 showed, that no position concentrates a disproportionate risk, taking into account how the chosen positions relate to each other.</p>\n<p>Sizing each position, also covered in Module 3, is what translates the allocation and diversification into concrete numbers: how much weight each position gets within the portfolio, consistent with its contribution to overall risk, not just with the investor's conviction in that specific idea.</p>\n<p>Finally, building a portfolio doesn't end at the moment of purchase. The tax cost of trades -- already covered in Module 5 -- and the future need to rebalance -- already covered in Module 4 -- are part of the criteria from the start, not an afterthought: a well-built portfolio anticipates that it will need to be reviewed over time, a topic the next lesson develops.</p>\n<h2>Example</h2>\n<p>An investor with a long time horizon and a risk profile that tolerates swings decides, based on their asset allocation, to put most of the portfolio into stocks and a smaller part into bonds. Within the stock portion, they diversify across several companies and sectors instead of concentrating the investment in just one; within the bond portion, they do the same across several issuers. Position weights have been set accounting for their contribution to concentration risk and how they relate to the rest of the positions.</p>\n<h2>Common mistakes</h2>\n<ul><li>Choosing the specific instruments first and deciding the asset allocation afterward, instead of the other way around -- the allocation should precede the selection, not follow it.</li><li>Confusing &quot;diversifying&quot; with &quot;accumulating many different instruments&quot; without watching the real correlation between them.</li><li>Building the portfolio without considering from the start that it will have a tax cost and will need rebalancing -- treating both as a later surprise instead of a design criterion.</li></ul>\n<h2>Summary</h2>\n<p>Building a real portfolio means applying, in sequence, the criteria already covered in this level: asset allocation based on risk profile and time horizon, diversification within and across asset classes, sizing each position based on its contribution to overall risk, and anticipating the tax cost and the future need to rebalance.</p>\n<h2>Self-check</h2>\n<p>Why should asset allocation be decided before choosing the specific instruments that will make up the portfolio?</p>\n<p>Why isn't diversifying the same as simply accumulating different instruments?</p>","sortOrder":1,"readingMinutes":7,"difficulty":"Intermedio","url":"/en/academy/portfolio-management/building-a-portfolio/how-do-you-build-an-investment-portfolio-step-by-step"}],"graphSummary":{"root":{"type":"concept","id":"84","depthFromRoot":0,"entity":{"type":"concept","slug":"dimensionamiento-de-posicion","term":"Dimensionamiento de posición","excerpt":"Criterio para decidir cuánto peso debe tener una posición en una cartera según cuánto riesgo de concentración introduce y cuán correlacionada está con el resto -- una herramienta para controlar su contribución al riesgo, no una fórmula universal."}},"depth":1,"returnedNodes":1,"truncated":false,"hasCycle":false,"nodes":[{"type":"concept","id":"84","depthFromRoot":0,"entity":{"type":"concept","slug":"dimensionamiento-de-posicion","term":"Dimensionamiento de posición","excerpt":"Criterio para decidir cuánto peso debe tener una posición en una cartera según cuánto riesgo de concentración introduce y cuán correlacionada está con el resto -- una herramienta para controlar su contribución al riesgo, no una fórmula universal."}}],"edges":[]},"relatedNews":[],"relatedEntities":[]}