One Prompt, One Stock, 360 Runs: How an LLM Gets a Trade Right and Still Can’t Be Trusted With It

On 2 February 2022 Meta lost $230bn in a day. I gave a language model one careful prompt and ran it 360 times on that print. It called the direction right 60 times out of 60 — and produced 13 different trades. Here are the nine pitfalls, and the skill that fixes them.