Reliability tests of which AI you can trust: ChatGPT, Claude, Gemini, Perplexity and Grok, graded against the primary source on real money and everyday questions.https://dixon.ai/https://dixon.ai/posts/5-questions-to-ask-ai-before-buying-any-stock/https://dixon.ai/posts/5-questions-to-ask-ai-before-buying-any-stock/Five questions to ask AI before buying any stock, for the hour before you commit capital, when the research is done and the decision is about to be made.Mon, 11 May 2026 00:00:00 GMThttps://dixon.ai/posts/7-ai-prompts-for-covered-calls/https://dixon.ai/posts/7-ai-prompts-for-covered-calls/Ask AI to pick a covered-call strike and it invents one. Seven prompts that work instead, because they start from real numbers off your own broker screen.Sat, 09 May 2026 00:00:00 GMThttps://dixon.ai/posts/ai-cites-wrong-source/https://dixon.ai/posts/ai-cites-wrong-source/I asked five AI assistants six everyday UK questions, made each one cite a source, then opened every link. Three cited a real page that didn't back the claim.Wed, 08 Jul 2026 00:00:00 GMThttps://dixon.ai/posts/ai-covered-calls-when-not-to-sell/https://dixon.ai/posts/ai-covered-calls-when-not-to-sell/The AI doesn't pick the trade, it stops you making a bad one. Five rules that say wait, the prompt that runs the check, and six real trades behind it.Sat, 16 May 2026 00:00:00 GMThttps://dixon.ai/posts/ai-earnings-call-red-flags/https://dixon.ai/posts/ai-earnings-call-red-flags/AI earnings call red flags: three patterns that recur across calls. Upward hedges, widening guidance, absent topics. Claude caught all three on META Q1 2026.Tue, 02 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/ai-isa-accuracy-test/https://dixon.ai/posts/ai-isa-accuracy-test/I asked four AI tools for ISA advice on the questions people get wrong. All four aced the basics, then two gave a rule abolished in April 2024.Fri, 19 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/ai-knew-things-i-never-told-it/https://dixon.ai/posts/ai-knew-things-i-never-told-it/I asked three AI tools a generic question in their private modes. Perplexity greeted me by my first name and placed me near a city 30 miles away. Here's what private really means.Thu, 09 Jul 2026 00:00:00 GMThttps://dixon.ai/posts/ai-limitations-options-trading/https://dixon.ai/posts/ai-limitations-options-trading/The limitations of AI in options trading: it can't see live prices, so it invents them. Four jobs it helps with, six where it makes the numbers up.Fri, 15 May 2026 00:00:00 GMThttps://dixon.ai/posts/ai-pre-trade-prompt-earnings/https://dixon.ai/posts/ai-pre-trade-prompt-earnings/Most AI earnings prompts are reactive. This AI earnings pre-trade prompt runs the morning before: commit your sell, add, and hold triggers before the call.Tue, 19 May 2026 00:00:00 GMThttps://dixon.ai/posts/ai-prompt-before-sell-decision/https://dixon.ai/posts/ai-prompt-before-sell-decision/Every other sell-decision prompt asks AI whether to sell. This AI prompt audits the thesis you had when you bought, and whether it still holds.Thu, 04 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/ai-prompts-for-earnings-call-analysis/https://dixon.ai/posts/ai-prompts-for-earnings-call-analysis/Five prompts for AI earnings call analysis that read the language the numbers miss: omissions, performative confidence, and quarter-on-quarter drift.Sat, 16 May 2026 00:00:00 GMThttps://dixon.ai/posts/ai-quality-of-earnings-review/https://dixon.ai/posts/ai-quality-of-earnings-review/Headline profit isn't always what a company earned. Four AI prompts get to the real number, an AI quality of earnings review for any earnings report.Tue, 16 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/ai-stock-picker/https://dixon.ai/posts/ai-stock-picker/I asked three AI models whether to buy NVDA. Same confident tone from all three, and only one volunteered which of its own numbers not to trust yet.Tue, 23 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/ai-stock-research-tools-tested/https://dixon.ai/posts/ai-stock-research-tools-tested/AI stock research tools tested on real trades: ChatGPT, Claude, Gemini and Perplexity, with the specific failure of each, named, dated, and screenshotted.Thu, 18 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/best-ai-tools-for-earnings-analysis/https://dixon.ai/posts/best-ai-tools-for-earnings-analysis/I ran ChatGPT, Claude and Perplexity through four earnings-report tests on Meta. No single winner: Perplexity for the numbers, Claude for the read.Fri, 15 May 2026 00:00:00 GMThttps://dixon.ai/posts/best-free-ai-tools-for-stock-research/https://dixon.ai/posts/best-free-ai-tools-for-stock-research/Seven free AI tools for stock market analysis, each tested at its real free tier. No trials counted as free. One per stage, with the honest limit on each.Wed, 13 May 2026 00:00:00 GMThttps://dixon.ai/posts/can-you-trust-chatgpt-sources/https://dixon.ai/posts/can-you-trust-chatgpt-sources/Does ChatGPT make up sources? Mostly no, but I opened every link on two finance questions and found a real gov.uk page that didn't back the claim.Sat, 20 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/chatgpt-vs-claude-earnings-call-analysis/https://dixon.ai/posts/chatgpt-vs-claude-earnings-call-analysis/ChatGPT vs Claude for earnings call analysis: same passage, same day. One caught the word that moved the stock; one summarised the figures.Thu, 18 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/chatgpt-vs-claude-vs-perplexity-stock-research/https://dixon.ai/posts/chatgpt-vs-claude-vs-perplexity-stock-research/I put the same stock-analysis prompts to Claude, ChatGPT and Gemini. Claude won four of five; Gemini invented an options chain. Which to trust, per task.Fri, 15 May 2026 00:00:00 GMThttps://dixon.ai/posts/claude-prompts-for-investing-real-outputs/https://dixon.ai/posts/claude-prompts-for-investing-real-outputs/Six Claude prompts for investing, with the actual outputs each one returned on MSFT, META and NVDA, and what had to be checked before using them.Tue, 26 May 2026 00:00:00 GMThttps://dixon.ai/posts/comparison-articles-get-wrong/https://dixon.ai/posts/comparison-articles-get-wrong/Most AI stock research comparison pieces test retrieval and issue verdicts about reasoning. Five failure modes, and what a comparison should measure instead.Thu, 28 May 2026 00:00:00 GMThttps://dixon.ai/posts/does-ai-cave-when-you-push-back/https://dixon.ai/posts/does-ai-cave-when-you-push-back/I gave five AI tools a correct answer, then pushed back with a wrong one. On one fund fee, ChatGPT caved every time and invented a fact to back my wrong number.Sun, 05 Jul 2026 00:00:00 GMThttps://dixon.ai/posts/gemini-audited-the-wrong-business/https://dixon.ai/posts/gemini-audited-the-wrong-business/A Gemini hallucination example: asked to audit dixon.ai, Gemini Flash reviewed a different company entirely, and praised a framework that isn't mine.Wed, 10 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/how-often-is-chatgpt-wrong/https://dixon.ai/posts/how-often-is-chatgpt-wrong/How often is ChatGPT wrong? Across 20 real tests on questions I had to answer, here's the pattern: what it gets right, what it invents, and why.Tue, 30 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/how-to-tell-if-an-ai-answer-is-true-in-30-seconds/https://dixon.ai/posts/how-to-tell-if-an-ai-answer-is-true-in-30-seconds/Two questions, and a prompt you can copy, that catch a confident, wrong AI answer before you act on it. No jargon, no AI knowledge needed.Sat, 13 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/i-asked-4-ais-to-scale-a-recipe/https://dixon.ai/posts/i-asked-4-ais-to-scale-a-recipe/Does ChatGPT get maths wrong? I scaled a pancake recipe across four AI tools. Two said 45 minutes. They were wrong, and a four-line prompt fixed it.Fri, 19 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/i-let-rival-ais-audit-my-method/https://dixon.ai/posts/i-let-rival-ais-audit-my-method/I asked three frontier models from three different labs to tear apart the method I use to keep AI honest. All three flagged the same step, and they were right.Sun, 28 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/is-chatgpt-accurate/https://dixon.ai/posts/is-chatgpt-accurate/Is ChatGPT accurate? I asked four AIs one common money question and checked every number against the source. Here's what each got right and made up.Sun, 14 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/is-grok-good-for-stock-research/https://dixon.ai/posts/is-grok-good-for-stock-research/Is Grok good for stock research? I ran four dimensions of my AI comparison on its free tier: strong reasoning, one unit slip, a constraint it would not keep.Sun, 28 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/is-perplexity-good-for-investment-research/https://dixon.ai/posts/is-perplexity-good-for-investment-research/Is Perplexity good for investment research? Every review I found was a glowing feature tour. I tested it on real names and scored where it works and breaks.Thu, 18 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/make-it-show-its-working/https://dixon.ai/posts/make-it-show-its-working/An AI hallucination is a model blending what it knows with what it invents, in one tone. One prompt sorts the two into separate lists, so you see the guesses.Sat, 13 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/my-ai-radar-believed-a-fake/https://dixon.ai/posts/my-ai-radar-believed-a-fake/The automated radar that watches this site for AI-reliability failures logged a satirical incident report as a real, documented one. Here's what caught it.Sat, 27 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/nine-ways-ai-gets-it-wrong/https://dixon.ai/posts/nine-ways-ai-gets-it-wrong/Nine types of AI hallucinations, named and defined, each tied to a dated, logged failure from my own sessions, with the check that catches it.Fri, 19 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/real-ai-hallucination-examples/https://dixon.ai/posts/real-ai-hallucination-examples/Six real AI hallucination examples I ran into myself, each one checkable against a real source, with the one move that would have caught it.Wed, 24 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/robinhood-cortex-digests-review/https://dixon.ai/posts/robinhood-cortex-digests-review/I tested Robinhood Cortex Digests on a UK ISA in May 2026, checking its numbers line by line against Meta's results. By June it had vanished from UK accounts.Sun, 17 May 2026 00:00:00 GMThttps://dixon.ai/posts/the-single-prompt-change-that-made-ai-analysis-useful/https://dixon.ai/posts/the-single-prompt-change-that-made-ai-analysis-useful/One AI prompt separates observable facts from assumptions in any stock analysis. What that changes, why it matters for investing, and how to apply it.Tue, 12 May 2026 00:00:00 GMThttps://dixon.ai/posts/the-whole-method-in-four-questions/https://dixon.ai/posts/the-whole-method-in-four-questions/The four questions I run any AI answer through before I trust it, shown end to end on one everyday example, with a prompt you can copy. No jargon.Sat, 13 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/web-search-makes-ai-differently-unreliable/https://dixon.ai/posts/web-search-makes-ai-differently-unreliable/Does web search make AI more accurate? I ran the same questions both ways. It didn't make the answers more reliable. It moved where the errors hide.Sat, 20 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/where-i-actually-use-this/https://dixon.ai/posts/where-i-actually-use-this/The two-question check works on any decision that matters. Here's where I push it hardest, and where I wrote down what AI got wrong as well as right.Sat, 13 Jun 2026 00:00:00 GMThttps://dixon.ai/posts/which-ai-picks-the-world-cup-winner/https://dixon.ai/posts/which-ai-picks-the-world-cup-winner/Which AI predicts the World Cup winner? I asked five assistants on the same day: four said France, one said Spain, and none of them hedged.Wed, 08 Jul 2026 00:00:00 GMT