Open Portfolio on OpenBB: A suite for asset managers

In this guest post, Alberto Gallini (PhD), Engineering Manager at Prima and former Bloomberg engineer, walks through Open Portfolio, an OpenBB Workspace App built for asset management. He contextualizes how traditional and alternative asset managers approach portfolio construction, then breaks down the specific APIs Open Portfolio exposes for position imputation, holdings evaluation, and performance attribution. After demonstrating each API with concrete examples, Alberto closes with technical details on performance linking algorithms, architectural scalability, and the OpenBB Copilot.

Portfolio Management Context

The financial landscape is broadly divided into managers of Traditional Assets and those focused on Alternative Assets, alongside Family Offices.

Among Traditional Asset Managers are:

Mutual Fund Managers, who oversee pooled investment vehicles;
Hedge Fund Managers, who typically employ complex strategies and leverage to target high returns;
Pension Fund Managers, tasked with investing plan assets to provide employee retirement benefits;
Endowment Fund Managers, who manage long-term pools of capital to financially support institutions like universities or charities.

The Alternative Asset Managers group includes:

Private Equity Managers, who invest in private companies using strategies like leveraged buyouts and venture capital;
Real Estate Managers, who focus on assets such as commercial properties, residential properties, and REITs;
Infrastructure Fund Managers, who invest in essential projects like roads, bridges, and utilities;
Commodities Fund Managers, specializing in raw materials such as oil, gas, and precious metals.

Finally, Family Offices are private wealth management firms dedicated exclusively to managing the assets of high-net-worth individuals and their families.

Asset managers, irrespective of their specific focus, employ a variety of strategies and portfolio construction techniques centered around defined parameters.

These parameters include establishing clear Investment Objectives, which cover Return Expectations (the desired rate of return), Time Horizon (the timeframe for goals), and Risk Tolerance (the acceptable level of risk).

A key function is Asset Allocation, which involves:

Diversification to spread investments across various asset classes like stocks, bonds, real estate, and commodities to mitigate risk
Asset Class Weighting to set the precise proportion of each asset
Rebalancing to periodically maintain the target allocation

Finally, they engage in Security Selection using three primary methodologies:

Fundamental Analysis, which involves scrutinizing a company's financial statements and management quality;
Technical Analysis, which uses charts and historical data to spot market patterns;
Quantitative Analysis, which relies on mathematical models and statistical techniques for decision-making.

Once the strategy has been set and assessed, a portfolio enters its daily lifecycle: trading is performed accordingly throughout the day and is settled by the back office at the close of business. The back office's output is then used the next day to reassess the strategy, and the cycle continues.

How OpenBB changes the game

Open Portfolio Solution is an OpenBB Workspace App designed to cover the left side of the portfolio lifecycle.

The current set of exposed APIs comprises the following functions:

Position Imputation: Converts a set of transactions into a reconciled, daily record of holdings.
Holdings Evaluation: Assesses a daily portfolio of holdings by computing the position weight, market value, exposure, and leverage.
Characteristics Indicators: Evaluates fundamental and other indicators at the position level and aggregates them at both the bucket (according to a chosen classification strategy) and total portfolio level.
Ex-Post Risk Analytics: Evaluates metrics at position and aggregate levels, including the standard deviation of returns, Value-at-Risk (VaR), and tracking error.
Index Fetching: Fetches the most relevant index constituents and uses their representation as a benchmark for user portfolios.
Total Return, P&L, and Market-Value charts.
Brinson Performance Attribution: Evaluates asset allocation and security selection performance. This solution is similar to the most common offerings available in the market.

Open Portfolio: API & use-cases

Impute Position

This API ingests a transaction file and its related field mapping JSON descriptor to create a portfolio of holdings. This portfolio consists of daily snapshots and is associated with a single** base currency** as the currency of denomination for the entire investment strategy. The API is capable of either creating a brand new portfolio or incrementing an existing one by appending a new set of holdings from a transaction delta.

While this API is exposed via a widget, it is primarily designed for batch processes aimed at daily portfolio creation and incrementation. Key features include:

Asset Recognition: Identifies assets and stores their tickers by using OpenFigi (via ISIN or BBGID) as the security master.
Corporate Actions: Reconciles corporate actions using a market data provider (e.g., Yahoo Finance is the default for Equity).
Custom Data: Allows reading of custom data, such as prices and corporate actions, if provided.
Data Storage: Stores daily snapshots and transactions in separate files to facilitate better diagnostics and audit processes.

Batches processes can be scheduled to call this API to periodically build/increment user portfolios in a local folder, ftp endpoint or s3 bucket and create a data/lake of portfolio-ready ready to be analyzed and compared with benchmarks.

Index Fetching

This API is designed to create index universes by fetching constituent data from tradingview.com and market data (prices and corporate actions) from Yahoo Finance. Since the data doesn't originate from the official index providers, the performance will not perfectly match the official indexes, which require original membership, weights, and returns. However, it offers a good proxy and allows for accurate historical performance attribution, as it eliminates pricing difference effects by using the same default provider (Yahoo Finance) for both portfolios and indexes.

Below is the Nasdaq Composite Index performance computed bottom-up by Open Portfolio in OpenBB and the top index price performance reported by tradingview.com:

Holdings Evaluation / Characteristics / Ex-Post Risk

This Holdings API delivers a series of portfolio snapshots within a specified time-frame (defined by a start and end date). Each portfolio snapshot is built upon a set of foundational indicators:

Asset Market Value (at the start and end of the day)
Asset Exposure
Weight

Basic Performance and P&L (Profit & Loss) indicators are then computed on top of these. Snapshots can also be enriched with Characteristics fields like P/E, P/CF, Earnings per Share (relying on fundamental data from Yahoo Finance) and ex-post risk analytics, such as standard deviation (std-dev), Value-at-Risk (VaR at 95% or 99% confidence), and tracking error. All computed analytics are then aggregated at the bucket and total portfolio level according to the selected classification rule.

Total Return, P&L and Market-Value

This is a simple yet powerful API designed to compare a portfolio's top-level performance indicators — such as P&L, market value, or returns — against a benchmark over a specified time period. If a classification strategy is applied, the API also returns these values at the bucket level. This tool is highly valuable for understanding:

How an investment strategy performs relative to an arbitrary benchmark over time:

The historical performance trend for each bucket defined by the classification strategy:

How the asset allocation across the investment strategy's buckets changes over time:

P&L breakdown into income, transaction and total:

and much more …

Performance Attribution

Performance attribution is a critical analytical process aimed at explaining a portfolio's returns relative to a benchmark and identifying the specific sources of excess return (alpha).

Essentially, it is the mathematical process of:

Disentangling the overall fund return into its component parts.
Relating those returns to the various risk-taking decisions made by the portfolio manager.
Quantifying which active investment decisions (e.g., asset allocation or security selection) succeeded and which did not.

In short, performance attribution serves as critical business intelligence by measuring the success or failure of investment decisions based on the underlying risks taken.

Open Portfolio isolates the trading and currency effect and identifies the local currency holding return as excess.

This is a very accurate approach for the Equity and ETF market where this solution is positioned.

The Performance Attribution implementation is based on the Brison methodology which is currently an industry standard exploited by many vendors like Bloomberg PORT, BlackRock Aladdin or Factset.

The Open Portfolio Performance Attribution fundamentally dissects a portfolio's active return (excess return over a benchmark) into the results of two primary, controllable decisions made by the portfolio manager:

Asset Allocation

Asset Allocation is the value added or subtracted by the manager's decision to weigh asset classes or sectors differently from the benchmark. It measures the impact of over-weighting asset classes that subsequently outperform and under-weighting those that subsequently underperform, based only on the benchmark returns of those asset classes.

Security Selection

Security Selection is the value added or subtracted by the manager's decisions within a specific asset class or sector. It measures the impact of holding specific securities that perform better or worse than the return of that asset class's benchmark, weighted by the portfolio's actual exposure to that class.

Leverage

This term measures the impact of derivatives in the portfolio. Their weight is basically removed from asset allocation and separately accounted into a global leverage effect.

The Performance Attribution also provides a trend-analysis mode showing the Attribution effects historically for each bucket (up to the constituents level if such level of transparency is required).

Here is an example of a test portfolio that is quite aligned in terms of asset allocation with the benchmark. The portfolio is outperforming the benchmark in October 2025, and the analysis shows the reason is the investment strategy is picking better stocks in the Technology sector. This is not only reflected by the higher returns of the sector but by the accurately measured security selection effect, computed daily and then linked over time.

Some Notes About Open Portfolio App

Performance Accumulation over time logic

Api like Holdings, Performance Attribution and Totals perform an important operation on the daily performance indicators (P&L and returns): they accumulate the daily values over time. While P&Ls are simply added, the returns are geometrically compounded according to the following:

This is done for both position level returns and bucket/top level returns which are aggregated as

The return components like transaction returns, holding returns, the contribution to returns and all the attribution effects are linked using the Carino Linking approach. The linking algorithms are important to keep the additivity of the return components and attribution effects over time. There are many linking algorithms, we preferred Carino as it is one of the most accurate — even if less intuitive than Menchero during periods of high volatility returns - and at the same time offers good stability on incremental linking (i.e., linking of pre-linked periods).

Performance Transparency

The Holdings API exposes all necessary fields for calculating and reconciling market values, P&Ls, and returns. This comprehensive data set makes it easy to verify all calculations and quickly identify any errors or inconsistencies in the input data, which is particularly useful when processing custom datasets.

Scalability

Thanks to OpenBB's flexible architecture, the Open Portfolio APIs are encapsulated in a portable Docker container that can be instantiated as many times as needed. The Widget that serves the OpenBB dashboards can be bound to different instances to isolate traffic and ensure dedicated computational resources per user, or even per widget. This capability allows you to configure your enterprise environment in a scalable and secure manner, offering access and visibility to resources based on role and responsibility.

Since the Open Portfolio APIs are primarily I/O-bound, this architecture ensures perfect horizontal scalability, guaranteeing no Service Level Agreement (SLA) degradation regardless of the number of terminals enabled to access the APIs.

OpenBB Copilot Integration

All widgets powered by the Open Portfolio API expose assets and indicators in a way that allows the OpenBB Copilot to extract meaningful information on the investment strategy, analyze it, and provide effective summaries and suggestions for tweaking and optimizing the strategy based on historical benchmark trends.

Interacting with the OpenBB Copilot on the AI chat side panel

If you want to access the app Alberto has built, feel free to connect with him on LinkedIn or reach out to our team.

OpenBB enables financial institutions to bridge their data with AI by providing the interface to build AI-powered analytics applications, securely and on their terms. Between a BI tool and a terminal, the OpenBB Workspace provides the infrastructure and interface for data visualization and AI-assisted analysis.

Check our Solutions to see other workflow examples.

TL;DR: We are open-sourcing the entire OpenBB product suite under a permissive open source license

Today is bittersweet.

On December 20, 2020, over the Christmas holidays, I wrote the first lines of Gamestonk Terminal, what would eventually become OpenBB. My flight home to visit my parents had been cancelled because of COVID, so I stayed in London and started building a tool to streamline my own investment research process.

At the time, the idea was simple: individuals (and firms) should be able to own their research platforms. They shouldn't have to adapt their workflows to whatever a data or software vendor decided to build. They should own the entire experience - from the data they connect to, to the interface analysts and PMs use every day, to the APIs, models, skills, tools and AI agents that increasingly form part of the investment process.

Over the last almost six years, OpenBB evolved far beyond anything I imagined when writing those first lines of code. We started as an open-source terminal and went on to build the SDK (now Open Data Platform), the OpenBB Bot, the OpenBB Workspace, the OpenBB Copilot, the Excel Add-in, and an ecosystem of applications created by our team, our partners and the community.

We kept innovating and being at the forefront of what user experience should be. I was prepared to die on the hill that if we were to become the financial infrastructure software for the buy-side and sell-side, then we could not monetize data. Monetizing data would have made us a data vendor. The margins would have been higher, but the incentive would have shifted from offering a better UI/UX to selling more datasets. Selling an infrastructure platform is incredibly challenging, for many reasons. And so we died on that hill. Along the way, we built an incredible community, reached millions of people through our open-source project, worked with some of the largest financial institutions in the world and assembled a team that consistently built far beyond what should have been possible for a company of 10 people. There is a lot to be proud of.

But despite all of that, we couldn't find the product-market fit needed to build a sustainable business around this vision within the time we had.

As a founder, I've always bet the house on the next customer, the next feature or the next launch to change the trajectory of the company. Until even just last weeks, when we announced self-serve Workspace Lite. If we were ever going to close doors, then we never wanted to look back and think "what if".

In hindsight, we could obviously have made different decisions - e.g., surrounding data, or going more vertical with clients and their workflows. But short-term monetization was not something I was prioritizing over where I thought the industry was heading. Ultimately, I wanted us to stand for something.

In the last phase of the company, I explored many paths to give OpenBB a better home. We spoke with larger companies that shared parts of our vision and tried to find a home where the products, and ideally the team behind them, could continue to grow. Ultimately, we weren't able to make that happen.

I left London with my wife to build OpenBB and dedicated almost six years of my life to it. So did the team. We built at the intersection of finance, AI, open source and software infrastructure, often working on problems before they became obvious to the broader market.

Before MCP existed, we had created our own API protocol so agents could interact with the data and analytics widgets in the workspace. In 2023, we built askobb, which let anyone ask investment research questions in natural language that required joining multiple different datasets together.

What this team created deserves to continue existing.

More importantly, I still believe the original vision is inevitable. The future of financial software is not a single platform every firm is forced to use. It is thousands of firms building environments that reflect how they actually work - their own data, internal systems, investment processes, risk models and compliance requirements. Increasingly, their own APIs, MCP servers, models and AI agents too.

If that future is coming, then the technology we built shouldn't disappear simply because we weren't able to commercialize it successfully.

It should become available to everyone.

Today, with the support of the team and OSS Capital, we are committing to releasing the entire OpenBB product suite under a permissive license. This includes OpenBB Workspace, Open Data Platform, OpenBB Copilot and the OpenBB Excel Add-in.

These products represent over 5 years of engineering, millions of dollars invested in R&D and thousands of decisions, experiments and iterations with users. They will become a foundation that individuals, startups, data providers and financial institutions can freely use, modify and build on top of.

We will share more details about the order and timing of each release as we complete that work. In parallel, we will determine the right long-term structure to steward the projects, support contributors and preserve what made OpenBB special in the first place. Existing customers and users of the hosted products will hear from us directly about timelines.

For the partners who built applications for the OpenBB ecosystem, I hope this decision makes your products even more valuable. You already did the work of turning your datasets and analytics into applications that users can interact with. Now, those applications will be able to run inside infrastructure that firms can fully own, extend and customize, while combining them with data and tools from other providers across the ecosystem.

The same applies to the broader community. Developers will be able to use the entire OpenBB stack as a starting point rather than rebuilding the same infrastructure from scratch. Firms will be able to deploy it, adapt it to their requirements and connect it to the systems where their differentiated knowledge already lives.

Over the years, many talented people helped make OpenBB what it is today - employees, contributors, partners. Every one of them left a mark on the product.

But I want to recognize the people who carried OpenBB to the very end. Through the uncertainty and the final stretch, they kept building. They are engineers, product builders, designers and operators who have worked across financial data, AI, developer infrastructure and open source. In alphabetical order, they are:

Andrew Kenreich, Head of Product Engineering - LinkedIn
Darren Lee, Software Engineer - GitHub, LinkedIn
Ihsan Saracgil, CPO - LinkedIn
José Donato, Software Engineer - LinkedIn, X, GitHub, Website
Juan Alfonso, Software Engineer - GitHub, LinkedIn
Minh Hoang, Head of Product - LinkedIn, GitHub
Ogonna Nnamani, DevOps - LinkedIn, Medium
Rita Figueiredo, Head of Marketing - LinkedIn, Website
Rita Soares, Head of Design - LinkedIn, Website
Theodore Aptekarev, CTO - LinkedIn, GitHub

To our customers: thank you for trusting a small team with such an ambitious vision.

To our partners: thank you for building alongside us and helping create a more open financial data ecosystem. I hope the next chapter gives you even more freedom to serve your users.

To our investors: thank you for believing in us, including when OpenBB was little more than an idea being built from my living room in London. In particular, I want to thank OSS Capital and Joseph Jacks for supporting this decision and enabling the technology to live beyond the company. Two people I want to name separately: Justin Hoffman and Larry Augustin - working with both of you made me a better founder, but more importantly, a better person.

To every contributor who opened a pull request, reported a bug, wrote documentation, answered a question in Discord, built an integration or simply told someone else about OpenBB: thank you. OpenBB would not have been possible without you.

Finally, to every person who spent part of their career building OpenBB: thank you. We pushed the industry forward and proved that world-class financial infrastructure can be built in the open. The commercial outcome doesn't change the quality of the work.

OpenBB didn't become the company I imagined when I started this journey. But the mission was always larger than the company, and I still believe the ideas behind it are right.

If, ten years from now, firms around the world are using OpenBB as the foundation for software they truly own - connecting their own data, building their own workflows and deploying their own AI agents - then what we built will have achieved something that lasts far beyond us; which was my goal all along: have an impact.

Thank you for one hell of a ride.

Didier Lopes
(LinkedIn, X, GitHub)