Build vs Buy (Trading Platform)

How to Build a Custom Trading Platform (2026)

This guide is for founders and CTOs asking a serious question: "Why not build our own trading platform instead of licensing MT5, MT4, or cTrader?" The honest answer is: you can — but it's expensive, hard, and operationally unforgiving.

We'll give you a realistic view of what a trading platform actually is (market data, OMS, risk, FIX, WebSockets, bridges and liquidity), what team you need, what it typically costs, and how to de-risk the build.

1) Build vs license: the honest decision framework

Platforms like MT5/cTrader dominate because they solve not just the UI — they solve connectivity, execution workflows, operational tooling, and ecosystem dependencies. For most brokers, the fastest path to revenue is licensing.

License when:

  • You need to launch in weeks, not months.
  • Your competitive edge is marketing, sales, or distribution — not execution micro-architecture.
  • You don't yet have a specialized team for OMS, risk, FIX sessions, and 24/7 operations.

Build when:

  • You need a proprietary UX and product flow that licensors can't support.
  • You need unique execution / routing logic or specific asset classes.
  • You want full control of roadmap, integrations, data model, and unit economics at scale.
  • You accept that the first version won't be perfect — and you can invest in iteration.

The most successful approach is usually hybrid: license to launch, then progressively build your own core capabilities (client portal, back office workflows, risk, analytics, data pipelines) while keeping execution stable.

2) What a trading platform actually is (not just charts)

A real trading platform is a set of services that must be correct under stress: spikes, outages, partial fills, price gaps, network jitter, and adversarial behavior.

Minimum platform modules

  • Market data: symbol specs, quotes, spreads, tick snapshots, streaming updates
  • Order Management System (OMS): order lifecycle, states, retries, idempotency
  • Execution adapters: FIX sessions or bridge connections to liquidity providers
  • Risk engine: pre-trade checks (margin, limits), post-trade monitoring, exposure
  • Accounts/positions: balances, margin, PnL, open/closed trades
  • Wallet/ledger: deposits/withdrawals, adjustments, reconciliation with PSPs
  • Client portal: onboarding, KYC, funding, account actions, statements
  • Admin/back office: approvals, risk controls, routing rules, support tooling
  • Observability: logs, metrics, tracing, alerting, audit events

3) Reference architecture (high-level)

The goal is to separate "what the client asked for" from "what the market executed" and from "what we record internally". This makes the system resilient and auditable.

Core data flows

  • UI → API Gateway: auth, rate limits, session control
  • API → OMS: create order intent, validate, route
  • OMS → Risk: pre-trade checks, margin, limits
  • OMS → Execution Adapter: submit to LP via FIX or bridge
  • Execution → OMS: acks/fills/rejects (idempotent handling)
  • OMS → Ledger: finalize positions, fees, adjustments
  • Market Data → WebSocket: broadcast quotes to clients

Storage choices (pragmatic)

  • PostgreSQL: canonical state (users, accounts, orders, ledger)
  • Redis: sessions, rate limits, ephemeral quote cache
  • ClickHouse: analytics, tick history, aggregated reports

4) Connectivity: FIX, WebSockets, data feeds, bridges

Your client app typically uses REST/WebSockets. The market typically uses FIX. You need both.

WebSockets (UI streaming)

  • Design for reconnects and backpressure.
  • Use snapshot + incremental updates (don't rely on only ticks).
  • Throttle and batch updates per symbol group (performance & mobile).

FIX API (liquidity & execution)

FIX looks simple until you run it in production: sequence numbers, resend requests, disconnect storms, partial fills, cancels, and session-level edge cases.

Your platform might implement FIX directly, or it might integrate through a bridge/aggregator. If you're already building a platform, plan FIX as a dedicated "connectivity layer" with strong observability.

You can also position your technical depth by linking to your API pages: FIX API, WebSockets, Data Feed

5) Security & compliance realities

A custom platform increases your responsibility. You're not just building features — you're building controls. Account takeover and payout fraud are real; audit trails and role separation are mandatory.

  • Authentication + optional 2FA
  • Session/device management
  • Rate limiting + WAF rules
  • Immutable audit events for KYC and payouts
  • Secure document storage for KYC

6) Team, roles, and timelines

If you want a realistic build, treat this like building a fintech product. The minimum team is not "two full-stack devs".

Typical roles

  • Trading systems architect: OMS, risk, execution models
  • Backend engineers: OMS, ledger, integrations (FastAPI/services)
  • Connectivity engineer: FIX sessions, bridge integration, performance
  • Frontend engineers: trading UI, order ticket, account UX
  • QA automation: market scenarios, edge cases, regression suites
  • DevOps/SRE: deployments, monitoring, incident response

Timelines (realistic)

  • MVP: 6–9 months with an experienced team
  • Production-grade platform: 12–18+ months (multi-asset + mature ops)

7) Cost ranges (and why it's expensive)

The cost is not only engineering salaries. It's also reliability work, test infrastructure, security, compliance, and ongoing operations.

  • Small MVP team (6–10): typically $60k–$200k/month depending on location and seniority
  • Production platform team (12–25+): $150k–$500k+/month
  • Timeline multiplication: if you don't have FIX/OMS specialists, time increases sharply

8) AI/ML: where it helps (and where it doesn't)

AI is useful when it reduces operational load and improves risk outcomes:

  • Fraud detection signals (behavior anomalies, device patterns)
  • Support triage, knowledge base, auto-summaries
  • Incident detection (log/metric anomaly detection)

AI does not replace execution correctness. Execution quality is infrastructure + liquidity + controls.

9) A realistic phased roadmap

Phase 1: foundation

  • Accounts, auth, roles, audit logs
  • Market data snapshots + WebSocket streaming
  • Demo trading / paper trading workflow

Phase 2: first live execution

  • OMS + risk checks
  • Single LP integration via FIX/bridge
  • Basic order types + trade history

Phase 3: operations

  • Ledger + deposits/withdrawals + reconciliation
  • Support tooling + compliance workflow
  • Monitoring + alerts + incident runbooks

Phase 4: scale

  • Multi-LP routing + failover
  • Advanced risk controls + limits
  • Analytics pipelines + performance dashboards

10) Outsourcing vs in-house: how to de-risk the build

If you're starting from zero, outsourcing to a specialized team often reduces risk. The key is structure: milestones, measurable deliverables, and continuous demos.

Our recommended engagement style

  • Discovery: requirements, execution model, asset scope, compliance needs
  • Architecture: services, data model, protocols, observability plan
  • Milestones: phased delivery with test criteria
  • Operational readiness: monitoring, incident response, audit trails

If you want to explore this seriously, start with a focused call. We'll map your target platform scope to a realistic plan: Talk to Brokeret

Deep dive: requirements checklist (what your spec should include)

If you're serious about building, you need a real specification. Below is a practical checklist teams use to avoid surprises.

Product requirements

  • Asset classes (FX, metals, indices, crypto, stocks, futures)
  • Account types, base currencies, leverage policies
  • Order types (market, limit, stop, stop-limit), partial fills, slippage rules
  • Execution model (A/B book, hybrid), routing rules, markups/spreads
  • Session behavior: trading hours, holidays, symbol halts
  • Client statements, exports, confirmations

Technical requirements

  • API contracts (REST + WebSocket), versioning strategy
  • Latency budgets (UI updates, order placement, confirmations)
  • Data model: canonical ledger vs derived balances
  • Idempotency strategy for orders and webhooks
  • Disaster recovery: RPO/RTO targets, multi-region strategy
  • Observability: traces, metrics, log correlation IDs

Operational requirements

  • Back office tools for support, compliance, and treasury
  • Manual interventions (cancel/close positions under policy)
  • Incident response runbooks and on-call rotations
  • Audit requirements: who changed limits, who approved payouts

Where FastAPI, Python, and ML fit

Python (often with FastAPI) is excellent for rapid development of API layers, admin tooling, and data pipelines. It's also popular for ML workflows (fraud signals, anomaly detection). The key is keeping execution-critical components isolated and performance-tested.

  • FastAPI: API gateway, user services, account services, admin APIs
  • WebSockets: quote streaming to client UI with throttling and batching
  • ML: fraud/risk scoring, abuse detection, monitoring anomalies
  • Execution: dedicated service with strict latency and reliability discipline

This is why the market depends on licensors: execution + connectivity + ops maturity takes time. The opportunity for a custom build is owning the product and operating model — not merely duplicating a charting UI.

FAQ

Frequently Asked Questions

If you need to launch fast, licensing is usually the best decision. Building a production-grade platform is expensive and requires a specialized team. Building makes sense when you need unique execution workflows, proprietary UX, specific asset coverage, or you want full control over roadmap and unit economics at scale.

Want a Realistic Build Plan?

We can turn "build our own platform" into a staged roadmap with clear milestones and risk controls.