Build vs buy: the real cost of trading infrastructure

Every team that automates a trading strategy eventually runs this calculation. Building looks cheap because the inputs are already paid for: you have engineers, the broker has an API, and the first version seems like a few weeks of work. The math feels obvious. It is also usually wrong, because the estimate covers the build and the actual cost lives in everything after.

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What the build estimate always misses

The first 80% of a broker integration is a demo. Orders go out, fills come back, everyone is pleased. The last 20% is the product, and it is the part that never ends. Rejected orders with undocumented causes. Websockets that drop mid session and take your fill events with them. Positions that drift from what the broker says, discovered at the worst moment. Broker API changes that land on their schedule, not yours. Risk checks you keep meaning to write properly. None of this appears in the original estimate, because the original estimate described software and this is an operation. Software gets finished. Operations get staffed.

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Put rough numbers on it

Run the back of the envelope math for your own team. A capable engineer costs somewhere north of $200,000 a year fully loaded. A serious first integration takes months, not weeks, once reconciliation, monitoring, and failure handling are real. After launch, plumbing maintenance quietly eats a meaningful slice of someone’s time forever, and doubles the day you add a second broker, because now there are two sets of formats, error codes, and quirks to keep aligned. Then add the cost that never shows up on a spreadsheet: every hour spent on plumbing is an hour not spent on the strategy, and the strategy is the only part that makes money. For a small team, that opportunity cost dwarfs the salary math.

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What buying actually gets you

Managed trading infrastructure collapses all of that into an API call. Anthid is one example: a single API for order execution, broker connectivity, live event streams, and risk controls, with brokers like Alpaca and Lightspeed behind it. You describe the outcome you want, and the platform handles retries, failures, reconciliation, and every broker’s quirks. Events arrive normalized and land in a durable ledger. Trading windows and order size limits are enforced before an order leaves. You also inherit numbers a small team rarely reaches alone: 99.99% uptime and median order acknowledgement of 42ms, with someone else carrying the pager.

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When building still wins

Sometimes it does, and pretending otherwise would be silly. If you run a large firm with a dedicated platform team, colocated hardware, and latency requirements measured in microseconds, the infrastructure is part of your edge and you should own it. The same goes if your strategy depends on broker behavior so unusual that no shared platform will model it. Those cases are real. They are also rare, and most teams citing them are three people with a Slack channel named #infra.

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How to decide in an afternoon

You do not need a committee for this one. Take a strategy you already have, point it at a managed platform’s paper trading tier, and see how far you get before dinner. Anthid’s free tier needs no credit card and no sales call. If you ship a working paper strategy in an afternoon, you have your answer, because the build option cannot even schedule its kickoff meeting that fast.