How to build an investment platform
The parts of an investment platform, from onboarding and suitability to orders, positions and reporting, the rules behind them, and an order to build it in.
What an investment platform does
An investment platform lets clients or advisers open accounts, set goals, invest, see what they own and get reports. It might be a robo-advisor, a trading app, an adviser portal, a fund investor portal or a family office dashboard.
Underneath, they share the same core: verified clients, suitability that decides what they may be offered, positions reconciled with custodians, and reports and documents built from that data.
The modules you need
Most teams need all of these in the end. The phased plan below sets the order.
Onboarding and KYC
Identity, tax status and source of funds checks, with documents stored.
Suitability and risk profile
Questions that set the client's profile and limit what they are offered, with the reasoning kept.
Portfolios and models
Model portfolios, rebalancing and drift alerts.
Orders
Order entry, routing to brokers and confirmations.
Positions and transactions
Holdings from custodians, reconciled every day.
Reporting
Performance, fees, tax and statements, built from reconciled data.
Documents and portal
Statements, notices and capital calls delivered securely.
Adviser tools
Client lists, reviews and suitability reports for advisers.
How the parts fit together
- 01
Positions ledger
An internal record of holdings reconciled with custodian data, with differences flagged.
- 02
Suitability rules engine
Versioned rules, so every recommendation can be traced to the rules in force.
- 03
Custodian and broker adapters
One adapter per custodian or broker.
- 04
Reporting pipeline
Reports generated from reconciled data, never from raw feeds.
- 05
Payment detail protection
Changes to bank details verified separately, to stop wire fraud.
Data model sketch
- 01
Client and account
Clients, accounts, owners, tax status and KYC status.
- 02
Risk profile
Answers, profile, date and rule version.
- 03
Position and transaction
Holdings and movements per account, by source.
- 04
Order
Instruction, route, fills and confirmation.
- 05
Report and document
What was sent to whom, when, from which data.
Systems it has to talk to
- 01
Custodians and brokers
Positions, transactions and order routing.
- 02
Market data
Prices, reference data and corporate actions.
- 03
KYC and screening
Identity checks, sanctions and PEP screening.
- 04
Fund administrators
Capital accounts and investor statements for funds.
- 05
Tax reporting
FATCA and CRS data and annual reports.
Rules to design for
Which rules apply depends on your market and product.
- 01
Suitability and conduct
MiFID II in the EU, FCA conduct rules in the UK and SEC adviser rules in the US set suitability, disclosure and record-keeping.
- 02
Client money and assets
Rules on holding client assets, usually with a regulated custodian.
- 03
Tax reporting
FATCA and the Common Reporting Standard.
- 04
AML
Investor due diligence and ongoing monitoring.
- 05
Operational resilience and AI
DORA for EU investment firms. AI commentary or advice needs human review.
From prototype to production
Build in this order so something real is in users' hands early.
- 01
Clickable prototype
Onboarding, the portfolio view and a sample report, tried by clients or advisers.
- 02
First product live
Onboarding, suitability, positions from one custodian and statements.
- 03
Orders and reporting
Order routing, performance and tax reporting.
- 04
Scale
More custodians, products, adviser tools and markets.
What drives the cost
These decide most of the budget. For a number based on your own scope, use the cost tool. OceanLab bills $30-50/hr or per milestone.
- 01
Custodians and brokers
Each one is an integration and a reconciliation.
- 02
Products and markets
Each product type and country adds rules and reporting.
- 03
Reporting depth
Performance, tax and fee reporting take careful data work.
- 04
Suitability logic
Rules that are explainable and versioned, and kept up to date.
- 05
Mobile trading
Real-time prices and orders on mobile.
Product builds that match this guide
Capstan - Fund Investor Portal and GP Console with Wire-Fraud Controls
Designed and built a clickable GP and administrator console for a New York private equity manager with a Delaware fund and a Cayman feeder: capital calls and distributions followed to settlement, an investor register with KYC and tax form status for each LP, and bank detail changes that need a signature, a callback and a second approver before any money moves.
Fjärd - Robo-Advisor App for ISK and KF Savings
Designed and built a clickable robo-advisor app for a Swedish digital investment manager: a suitability-based portfolio recommendation with its costs shown before investing, managed ISK and KF accounts that rebalance automatically, goals with projections, ISK tax estimates, and deposits and withdrawals signed with BankID.
Kinfold - Family Office Platform with Look-Through Net Worth Across Trusts and Companies
Designed and built a clickable family office platform for a Hong Kong single family office serving a three-generation family: one look-through net worth in HKD across trusts, holding companies and banks in six jurisdictions, an ownership map, an asset register with valuation ages, and a capital call calendar with four-eyes payment approval.
Pregão - Stock and ETF Trading App with the Income Tax Explained
Designed and built a clickable investor app for a Brazilian broker trading B3 stocks and ETFs: patrimônio at a glance, a market overview, an asset page with an order ticket that shows the lot and fractional split before sending, a portfolio at average price, and a tax centre that works out the monthly DARF.
Sextant - Multi-Custodian Portfolio Reporting with Advisor-Reviewed AI Commentary
Designed and built a clickable portfolio reporting platform for a Denver investment adviser with client assets at three custodians: daily reconciliation against custodian files, household views with performance gross and net of fees, and quarterly AI commentary that may only cite engine numbers and needs advisor and compliance sign-off.
Waymark - Advisor Portal with Suitability Reports Built From the Case
Designed and built a clickable advisor portal for a UK wealth firm's financial planners: a daily home with reviews due and alerts, a segmented client book, a Client 360 for every household, an advice case board and a suitability report builder that will not issue a report until the checks and approvals are in place.
Two ways to work with OceanLab
Project build
We design and build the system as one project. It starts with a clickable prototype your team tries before any production code is written. Pay per milestone (outcome-based) or hourly at $30-50/hr, depending on role and seniority.
Embedded engineers
Our engineers join your team on a flexible monthly retainer. Part-time is fine and it runs month to month, with hours that overlap the US, UK and Europe, the Middle East, and Australia and Asia. Outcome-based or $30-50/hr.
Questions
Do we need our own custodian?
Usually not. Most platforms work with regulated custodians and brokers, and focus on onboarding, advice, reporting and the client experience.
How do you keep reports right?
By reconciling positions with custodians every day and building reports only from reconciled data, with differences flagged before reports go out.
Can AI write portfolio commentary?
It can draft it from the data, with an adviser reviewing and approving each piece before it is sent.
