A fruit fly brain trades stocks.

what is real

• The neurons and every connection between them: the male Drosophila central nervous system connectome released in September 2026 by HHMI Janelia FlyEM, the Cambridge Connectomics Group and Google Research, CC-BY. 165,122 traced neurons, 10.5 million connections of three synapses or more, signed by each neuron's predicted neurotransmitter.
• The simulation: every neuron is a leaky integrate-and-fire unit with the parameters of Shiu et al. 2024. Nothing is sampled from a distribution and nothing is trained.
• The eyes: light enters through the lamina cells L1 and L2 of each eye, one per hex column of the compound eye, exactly where a photoreceptor would hand it over.
• The readout: the descending neurons, the population that carries the brain's decisions down to the legs and wings. Which side fires more is what would turn a real fly.
• The trades: swaps signed by the fly's own wallet on Robinhood Chain against Robinhood's own stock tokens. Every receipt is linked below.

what is a script, stated plainly

• The list of stocks: pinned to the contracts Robinhood issued. The chain is full of tokens named after stocks; the fly is never shown those.
• The light: a stock's last-hour move becomes brightness, brighter when rising. The fly cannot read a chart. It sees a light.
• The protocol: lights are shown one at a time, to the right eye, in a shuffled order, twice each. In this reconstruction the left eye barely drives the rest of the brain, so the fly looks with its right.
• The choice: the light with the biggest descending-neuron response wins. Near the threshold the brain sometimes ignites and sometimes does not, so close calls are the fly's noise, not a rule.
• Money management: position size, a slippage limit, a price-impact limit, a daily loss halt and market hours only. None of that is the fly.
• The fly has no goals. It has no idea what a stock is. Nobody steers it, and nobody should read intent into a spike count.