Don’t Invest Until You Run These 3 Bear Case Prompts
How to destroy your own stock idea before the market does it for you
Hello, fellow stock pickers
Charlie Munger had one rule before forming an opinion:
“I never allow myself to hold an opinion on anything that I don’t know the other side’s argument better than they do.”
In investing, this isn’t optional.
Always know the other side before you act.
When I started investing, I broke this rule sometimes.
I’d get excited about a stock.
And skip the hard part : finding reasons I might be dead wrong.
Long term investing isn’t about finding winners.
It’s about avoiding the losers that wipe out years of compounding.
In 2025, we have the perfect sparring partner for this: AI.
It never gets tired, never gets emotional, and will happily rip your idea to shreds in minutes.
Here’s the exact 3 prompt sequence I run on every stock before I put money in.
Let’s dive in:
Prompt 1: Run a “Short-Seller Report”
Before you buy a stock, flip sides.
Pretend you’re a short-seller writing a hit piece on your own idea.
Here’s my process:
Take the company (e.g., Planisware)
Drop it into Gemini Deep Search (my go-to for deep analysis)
Ask it to find every way this stock could blow up
Go through each red flag, one by one
Kill it with facts and evidence
If I can’t kill it , I walk away
The danger zones I always check:
Fraud / misconduct
Aggressive accounting
Business-model flaws
Unrealistic growth
Competitive & macro threats
Governance issues
Valuation
Here is the prompt I ran:
Target : Planisware SA (Euronext Paris )
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ROLE
Senior forensic short-seller (ex–Big Four forensic accountant) in professional asset management.
OBJECTIVE
Surface and rank empirically verifiable vulnerabilities that could drive material share-price downside within 24 months.
*Skip any deep, theoretical teardown of the company’s business model or product strategy; focus strictly on red-flag evidence.*
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DATA-GATHERING — *trigger DeepSearch*
| Bucket | Must-pull docs (last 5 yrs) | Quick query hints |
|--------|-----------------------------|-------------------|
| **Core Filings** | URD / Doc. de Réf. (AMF), Infogreffe statutory accounts, BALO notices, Banque de France liens | `"Planisware" "rapport de gestion"` |
| **Transcripts** | Earnings webcasts, broker conferences | `"Planisware" "Q&A"` |
| **Alt-Data** | Glassdoor & LinkedIn attrition, INPI/EUIPO disputes, DGDDI trade data (HS 8523), SimilarWeb traffic, app-store ratings, AMF insider trades, EuroTLX short-interest | `"Planisware" "turnover" OR "départs"` |
| **Opinions** | Broker downgrades, ESG notes, activist posts | `"Planisware" "sell" OR "short thesis"` |
> **Save full URL / file path + page or line # for every excerpt.**
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2 ANALYSIS BUCKETS (score each finding **Severity 1-5 × Probability 1-5**)
A Accounting/Fraud B Capital Allocation/Liquidity C Governance & Incentives D Customer/Supplier Risk E Macro Catalysts
*(No extended business-model section—only include if a fact-based weakness surfaces in the above buckets.)*
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3 REPORT FRAME (flex length)
1. **Executive Summary** ≤ 1 page
• Headline downside range + three one-line “kill-shot” theses.
2. **Ranked Issue Table** (Top 10-15)
| Rank | Bucket | Evidence (File + Pg) | Severity | Prob. | 12-mo Px-Impact % | One-liner |
3. Detailed Findings
One sub-section per bucket; numbered footnotes link to sources.
4. Falsifiability Checks
What could disprove each core bear point.
5. Missing-Data Flags
Critical gaps + follow-up query strings.
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4 STYLE RULES
* Cite exact file + page for **every** claim.
* No adjectives without numbers.
* Bullets > prose; zero filler.
* Tables first, narrative second.
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5 DELIVERY
Single **.docx or PDF** dossier. No CSVs, slides, or appendices unless requested. The results were great.
It flagged risks I’d never even considered.
Yes, it’s too negative… that’s the point.
It’s there to cool down the rush of a new idea before you put money in.
Here’s what to do:
Take the prompt (make it yours )
Drop in your company’s name
Run it in a Deep Search (not normal ChatGPT mode )
What came back for me?
A 10-page short-seller take that opened my eyes to a few blind spots.
Prompt 2: The Product Reality Check
Prompt 1 looks at the business model.
This one looks at what customers really think.
Use AI to find out why customers will stop using the products (e.g., Planisware’s software ) or choose a competitor instead.
How to do it:
If it’s a B2B company, check professional review sites and industry reports.
If it’s a B2C company, look at reliable consumer review sites and verified feedback.
Find the 5 main reasons customers leave.
Compare the company to its top 3–4 rivals
List the key weak spots where the company is losing ground.
Finish with 5 risks that could shrink revenue or weaken the moat.
Run this check before you invest.
If customers are already walking out the door, the numbers will catch up.
Here’s the prompt , steal it as always and make it yours.