THESIS SpaceX just pulled off the largest IPO in history (fixed $135/share on June 12, +50%+ in three days, briefly ~$2.6T valuation); Anthropic and OpenAI filed confidentially. Four decades of IPO history point to a boring answer on whether to jump in: probably not yet. ("IPO" = the old joke "It's Probably Overpriced.") The 2026 IPO wave is a readout of how hot the market is, not a buy signal — SpaceX, OpenAI and Anthropic belong on the watch list, not the impulse-buy list.
THE IPO POP MIRAGE - The offering price and the opening price are two different numbers; individual investors usually pay the second. - The first-day pop goes to whoever got an allocation, not the business or most public investors. - Rivian priced at $78, closed day one at $101, hit $172 a week later (+70%, briefly third-most-valuable automaker ahead of Ford and GM) — that was the peak; down 80%+ from that first-day close, ~$16 today. - Cerebras priced at $185, closed day one at $311 (+68%); a month later ~30% off its peak. - SpaceX tried to be fairer — skipped book-building theater and reserved an unusual 30% for individuals — but rose 50%+ in three days anyway, leaving less room for error.
WHAT 40 YEARS OF DATA SAY - IPOs tend to underperform, and by a lot. Three built-in disadvantages: limited operating history (the S-1 shows the past), insider selling (lock-ups expire ~6 months), information edge (the best investors saw the company years earlier at lower valuations). - Jay Ritter (University of Florida finance professor) built one of the definitive IPO datasets. Across thousands of operating-company IPOs with ≥$100M in sales, measured from first-day close, the five-year record: 50% posted negative returns, 30% lost half their value or more, only 24% became multi-baggers (+100%). - IPOs lag comparable companies most from 6 to 24 months after listing (around lock-up expiry). - 3-year window patterns: Size matters (under $100M sales trailed the market by ~34%; over $500M by just ~4%); Profitability helps (profitable issuers underperformed ~13%, unprofitable ~31% — none of the megacaps heading for IPOs are profitable); VC backing boosts odds (venture-backed trailed ~14% vs ~25% for others).
THE FIVE-RULE IPO PLAYBOOK (Bertrand's own rules) 1. Avoid the IPO hype — let initial open-market volatility pass. 2. Wait for the second earnings call — the S-1 is a snapshot; two quarters draw a trendline. 3. Nibble in year one — a small starter position; if a 50% drawdown would damage your portfolio or sleep, it's too big. 4. Anchor to valuation — missing a 20% move is not a disaster; buying perfection-priced is. 5. Give it time — many great stocks go nowhere their first few years; multi-baggers rarely require buying on day one. (Buffett: "It isn't worth spending five seconds thinking about IPOs"; IPOs come to market when sellers choose the timing.)
SPACEX, OPENAI, OR ANTHROPIC? - None has shown how it behaves under public-market pressure; margins at maturity uncertain, future growth not guaranteed. - They may become defining franchises of the next decade, but owning them on day one at peak-euphoria valuations before a single public quarter is a weak case. - Better move: put them on your watch list. Let them report, let the first wave of excitement pass, let insiders sell, let expectations move from story to numbers.
KEY FIGURES - SpaceX: $135/share fixed price (June 12), +50%+ in three days, briefly ~$2.6T valuation, 30% of the deal reserved for individuals - Rivian: priced $78 → $101 day-one close → $172 peak (+70%) → ~$16 today (down 80%+ from first-day close) - Cerebras: priced $185 → $311 day-one close (+68%) → ~30% off peak a month later - Ritter dataset (≥$100M sales, from first-day close, 5-yr): 50% negative, 30% lost half+, only 24% multi-baggers - 3-yr underperformance: under $100M sales ~−34% vs market; over $500M ~−4%; profitable ~−13%, unprofitable ~−31%; VC-backed ~−14% vs ~−25%
EDUCATION HARVEST (Step 3.6) - Concept: The five-rule IPO playbook (avoid hype / wait for the 2nd call / nibble year one / anchor to valuation / give it time). - Concept: "IPO = It's Probably Overpriced" — the first-day pop is a mirage; offering price ≠ opening price. - Reference/dataset: Jay Ritter's IPO returns dataset (University of Florida) — the definitive 40-year IPO underperformance record.
SECURITIES NAMED - SPCX (SpaceX, now public), RIVN (Rivian), CBRS (Cerebras), F (Ford), GM (General Motors) — Neutral/referenced illustrations. - Private: Anthropic, OpenAI — "watch list, not impulse buy".