EXTRACTOR
A real fruit-fly brain, the MaleCNS connectome, deciding BUY / HOLD / SELL on U.S. stocks. It's measured against brains with scrambled wiring, to see whether the fly's real wiring adds anything.
How Extractor decides, every trading day
After a profitable day, the next day starts with a pulse into the dopamine (PAM) neurons. Nothing learns: the wiring never changes. Which neurons stand for which feature, and which motor neurons mean "buy", is a random seeded assignment, because biology says nothing about stocks.
The brain in 3D
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Neuron positions are the real soma locations from MaleCNS. In the "thinking" videos, each group glows with the firing recorded that day by the locked model; the larger dots are individually sampled neurons with their exact spike counts. Those videos appear once the AAPL lock exists.
The fly
An adult male Drosophila melanogaster. Its whole central nervous system (brain, optic lobes and ventral nerve cord) was sliced into millions of thin sections, imaged by electron microscope and reconstructed neuron by neuron.
- dataset
- MaleCNS v1.0: Janelia (HHMI) with Google Research; published in Cell, Sept 3, 2026
- license
- CC-BY 4.0, public download
- loaded here
- 211,577 annotated bodies (164,506 with a cell type) and 26,028,386 connections
- signs
- from predicted neurotransmitters: GABA and glutamate inhibit, the rest excite
- model
- leaky integrate-and-fire neurons: a simplification, not a living fly
The experiment's rules
- train
- 2016–2021: the only period allowed to shape any parameter
- test
- 2022–2025, run once with locked parameters. Any change to code, thresholds or data voids the lock.
- controls
- 3 random-wiring brains, 3 shuffled-weight brains, 200 coin flips, buy & hold, momentum, mean reversion
- edge means
- beating every control brain, 95% of coin flips, momentum and buy & hold
- seeds
- Extractor is re-run with 3 other neuron assignments, to check the result isn't just luck of the draw
- same rules
- every arm gets the same data, fills, fees, slippage and risk limits
What this is not
- Not live trading. No orders go to any broker.
- Not intraday: one decision per day, on daily bars.
- Not proof of anything yet: no locked test has finished.
- Not a brain that "understands" markets: its inputs are four numbers it never learned to read.
- Not connected to Robinhood, which has no official stock-trading API.
The brain
Runs
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Results: Extractor vs. control brains
No locked test has finished yet. Results appear here once one does.
Replay: Extractor's neurons, day by day
The replay appears once the AAPL lock exists, about 2 hours into the run. It re-runs the locked Extractor over the 2016–2021 training period and records its neurons every day. The 2022–2025 replay unlocks only after the official test report exists.
Neuron firing, last 160 trading days
Each row is one neuron. Brighter means more spikes that day, with each group's colour scaled to its own busiest moment so the quieter motor neurons stay visible.