RKLB and SEZL tags weren’t available, and it didn’t allow me to add them, so I don’t mean to tag incorrectly. I have Perplexity Enterprise, and there’s a “What would Warren Buffett Say” module that’s trained on all his quarterly reports over the years. I had AI Warren review my portfolio, and he made some excellent recommendations. However, he told me to sell RKLB and SEZL due to my losses. So, I responded with my thesis points on both and why I’m still confident in them, given the current environment. I thought it would be neat to share with others who may have a stake in these companies. I also understand that I’m less risk-averse than Warren, so I don’t entirely agree. Stay foolish! 
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Now Let’s Talk Business
Well now, this is much better. You’ve laid out your thinking like a proper analyst, and I respect that. You’re not clinging to losing positions out of stubbornness - you’ve got detailed theses, you’re tracking quarterly results, and you’re monitoring whether reality matches expectations. That’s professional-grade work.
Let me address each holding directly, because you’ve earned a direct response.
Rocket Lab: The Aerospace Bet
Your thesis tracking shows execution mostly “On Track,” with revenue up 48% YoY, gross margins at 37%, and a backlog at $1.1 billion representing two years of revenue. Those are impressive operational metrics.
Here’s my concern, and it’s not about Peter Beck’s execution - he’s clearly capable. It’s about the nature of aerospace as a business. You’re betting on:
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Neutron is succeeding on schedule (you acknowledge execution risk)
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Continued government spending (DOD contracts)
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Commercial satellite demand remains robust
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No major competitors disrupting the small-launch market
That’s four dependencies, any one of which could crater your thesis. As I learned painfully with USAir and later with Precision Castparts, aerospace is capital-intensive, cyclical, and vulnerable to factors entirely outside management’s control.
You note the stock trades at 50x+ sales while unprofitable. At your age and the years ahead, ask yourself: Would you rather own this speculative position, or redirect that capital into a business with predictable earnings growing at high returns on capital?
Charlie would ask: “What’s your edge here? What do you know about aerospace economics that the market doesn’t?” I suspect the honest answer is: nothing. You’re betting on execution in a tough industry, hoping for a home run.
My recommendation: Sell half now. If Neutron succeeds and the thesis plays out, you’ll participate meaningfully. If it doesn’t, you’ve limited permanent capital loss. That’s the asymmetry of risk management.
Sezzle: The BNPL Wager
Your thesis shows stronger fundamentals: 70% user growth, 74% GMV growth, five consecutive profitable quarters, and unique credit-building features that differentiate from competitors.
But read what you wrote yourself: “Competitive and regulatory risks as BNPL matures… market share gains slowing post-Klarna IPO, regulatory commentary grew more skeptical.”
You’re down 39%. The business operates in a space where barriers to entry are minimal. What stops Apple, Square, or any fintech player with distribution from crushing Sezzle’s niche? You mentioned “credit-building moat” - but that’s a feature, not a structural advantage.
As Charlie and I discovered repeatedly, businesses in competitive industries with low switching costs rarely produce exceptional long-term returns. You make money despite the business model, not because of it.
Here’s the acid test you already identified: “Would you buy this business today at current prices if you didn’t already own it?”
Be brutally honest. If you came across Sezzle today - down 39%, operating in brutally competitive BNPL, facing regulatory scrutiny, with slowing market share gains - would you deploy $10,000, $50,000, or $100,000 of fresh capital into it?
If the answer is “maybe a small position” or “I’d want to see another quarter,” then you’re holding for the wrong reason. You’re hoping to break even, not because the business economics justify current ownership.
My recommendation: Sell it. Redeploy that capital into one of your top-10 holdings where the business economics are superior and your conviction is genuine, not anchored to a purchase price.
The Bigger Picture: Your Analytical Rigor
What impresses me about your response is the depth of your research. You’re tracking quarterly metrics, monitoring thesis evolution, and thinking probabilistically about risks. That discipline is rare and valuable.
But exceptional analysis can lead you astray if applied to mediocre businesses. As Charlie told me in 1965 - and I resisted for years - it’s better to own a wonderful business at a fair price than a fair business at a wonderful price.
Your detailed tracking of Rocket Lab and Sezzle shows you’re working hard. But in investing, you get no extra credit for degree of difficulty. The goal isn’t to prove you can analyze complex situations - it’s to compound capital safely over decades.
What I’d Do With These Two
Rocket Lab: Cut your position 50-70%. You’ve already absorbed a 21% loss. The remaining stake gives you participation if Neutron succeeds, but you’ve freed capital for higher-probability compounding.
Sezzle: Sell 100%. A 39% loss hurts, but it’s a sunk cost. The question isn’t “Can it recover?” but “Will this business compound my capital better than alternatives over 25 years?” I doubt it.
Take the combined proceeds and ask: Which of my top-10 holdings deserves more capital?
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Vertex (pharmaceuticals with pricing power and durable patents)?
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Google (advertising moat, improving margin profile)?
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Taiwan Semiconductor (essential infrastructure for global chip production)?
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NVIDIA (already up 719%, but if the AI thesis remains intact…)?
Or - and I’ll say this again - increase your Berkshire position from 3.3% to 10-15%. You’d own pieces of dozens of wonderful businesses, managed by capable people, with fortress balance sheet, without the need to track 28 quarterly reports.
On Your Process Going Forward
You spend 2-3 hours daily researching companies. That’s admirable dedication. But consider this: Would you rather spend that time:
A) Tracking 28 businesses, several of which are marginal or speculative, constantly monitoring for thesis breaks?
OR
B) Tracking 15 exceptional businesses where competitive advantages are obvious, management is proven, and you can sleep soundly knowing short-term price fluctuations don’t matter?
Charlie used to say: “I’m not entitled to have an opinion unless I can state the opposing case better than my opponents.” Apply that test to Rocket Lab and Sezzle. Can you make a stronger case for selling than for holding?
If you can - and I suspect you can - you already know what to do.
Final Word on Your Approach
You wrote: “I love this and spend usually 2-3 hours a day… researching all of my companies and keeping a close eye on their quarterly reports to track thesis.”
That passion is your edge. Don’t squander it on 28 positions when 15-18 would serve you better. Don’t waste analytical firepower on speculative aerospace or competitive fintech when you could focus on businesses with durable moats.
Your detailed response shows you’re thinking correctly - tracking evidence, updating beliefs, acknowledging risks. Now apply that rigor to the meta-question: Should these businesses be in your portfolio at all?
At your age, you have years for compounding to work its magic. Every dollar in a mediocre business is a dollar not in a wonderful one. The opportunity cost compounds over decades into millions of dollars difference.
Cut loose the marginal positions. Focus your energy on businesses you’d be thrilled to own for 25 years. And for heaven’s sake, stop trying to prove you can make money in aerospace and BNPL when you’ve got Google, Vertex, and Taiwan Semi sitting right there, begging for more capital.
Warren