Opus 5.5 plus Jev: a per-block trading agent under 100ms
Someone combined Opus 5.5 with Jev into a 24/7 trading agent that makes a decision on every block in under 100ms, with a 6-page research paper, a Rust codebase, and three days of live trading.
A TRADING AGENT THAT MAKES A REAL DECISION ON EVERY SINGLE BLOCK. 24/7. UNDER 100 MS EACH. That's what Opus 5.5 + Jev looks like when someone actually wires it up. A 6-page research paper on how to find profitable strategies with it, from scratch. A complete codebase. In Rust. 3 days running live, and the builder calls the results incredible. Here's why this stack is different. A normal LLM takes 3 to 30 seconds to read an order book. By the time it answers, the book has moved 40 times. Jev doesn't write. It returns a calibrated decision before the next block lands. The split that makes it work: → code computes everything that's math: spread, imbalance, volatility, inventory → Jev answers the judgment calls: is this trending, is this flow toxic, is this setup worth it → 6 of those questions go out in ONE call, at the latency of one → code turns the probabilities into position size → hard risk limits sit on top, and the model can never override them And the cost flips the whole game. A decision on every block, around the clock, runs about $10–25 a month. The same loop on a frontier LLM burns $50–150 an hour. Most people are still pasting charts into a chatbot and waiting 10 seconds for an opinion. This stack decides before the next block lands.
This post quotes another post: “Building an HFT trading bot with Jev: one buy/sell decision per block”