> ## Content Index > Fetch the complete content index at: https://onchain-fx.ghost.io/llms.txt > Use this file to discover other available public pages before exploring further. # Teaching a machine what BRL looks like - URL: https://onchain-fx.ghost.io/teaching-a-machine-what-brl-looks-like/ - Published: 2026-09-17T03:22:08.000Z - Updated: 2026-09-17T14:59:28.000Z - Description: A price is not just a number. It is a venue, a timestamp, a size, a liquidity condition and a settlement path. - Author: Guilherme Bissoli - Tags: Market Notes, BRL, Market Structure, Coins Learning, #lang-en Before an agent can reason about FX, it needs to understand what a price actually means. A price is not just a number. It is a venue, a timestamp, a size, a liquidity condition and a settlement path. Most systems — human or machine — collapse all of that into a single float and call it "the rate." That collapse is where most reasoning errors about markets begin. ## Four kinds of price, not one Before a machine can reason about BRL, it has to be able to tell these apart, because they answer different questions and are frequently confused with each other: Core distinctions **REFERENCE PRICE** — a published benchmark, useful for comparison, not necessarily tradable. **MARKET PRICE** — what venues are currently quoting, before size or settlement are considered. **EXECUTABLE PRICE** — what you could actually transact at, for a given size, right now. **CLIENT PRICE** — what a specific counterparty actually charges a specific client, including their margin. A model that answers "what's the USDBRL rate" without knowing which of these four it's being asked for isn't wrong so much as it's answering a different question than the one that was meant. ## A market observation is a structured object, not a number To reason correctly, a machine needs a market observation to carry enough structure to answer follow-up questions honestly. At minimum, that means holding all of the following together, not just the number that gets displayed: instrument venue bid ask mid depth size timestamp timezone reference\_usdbrl stablecoin\_usd\_price market\_session settlement\_context source freshness Drop any one of these and you lose the ability to answer a question that will eventually get asked: was this quote from a venue with real depth, or a thin one? Was it fresh, or stale by the time it was used? Was it comparable to the reference rate, or was the reference rate itself from a different session? ## Derived objects — where the actual insight lives The raw observation is the input. The objects worth reasoning about are derived from it: Derived objects **STABLECOIN PREMIUM** — the gap between a stablecoin's traded USD price and its peg. **BRL DIGITAL BASIS** — the spread between the on-chain USDT/BRL-implied rate and the reference USDBRL rate. **EXECUTABLE SPREAD** — the realistic bid/ask a given size could actually clear at, not the headline spread. **ROUTE COST** — the full cost of a specific path from currency A to currency B, of which the spread is one term. None of these derived objects can be computed correctly from a single number. Each one requires the underlying observation to still be intact — the venue, the size, the timestamp, the settlement context — which is the entire argument for treating a price as a structured object from the moment it's captured, not after the fact. ## Why this matters before an agent trades anything An agent that's asked to reason about a route, compare two quotes, or flag a stale price is really being asked to operate correctly across reference, market, executable, and client price simultaneously — and to know which one it's looking at at any given moment. Teaching that distinction first, before any trading logic, is what separates a system that understands markets from one that's pattern-matching on a number. --- *Before teaching a machine to trade, I want to teach it what a market is. BRL is a good place to start.* --- ## Related reading [The database is not the operating system](https://onchain-fx.ghost.io/the-database-is-not-the-operating-system/) — on why data infrastructure needs to behave like an operating system, not just a database. [What does it actually cost to move $10 million through Brazil?](https://onchain-fx.ghost.io/what-does-it-actually-cost-to-move-10-million-through-brazil/) — a CFO framework for measuring what a cross-border route actually costs, not just its headline FX spread. --- **Follow the money through Brazil.** ONCHAIN FX covers markets, capital, stablecoins, technology, infrastructure and the systems behind moving serious money. Get the next note in your inbox. [Subscribe](#/portal/signup) Moving meaningful volume through Brazil? [Talk to us.](https://onchain-fx.ghost.io/about/)