Fama-French Factor Analysis
of AI Stocks vs. the Dotcom Bubble
Do the Fama-French three- and five-factor models explain excess returns in the Magnificent Seven AI portfolio? How do factor loadings compare to the 1990s dotcom bubble tech stocks?
Project Overview & Portfolios
We construct two equally-weighted historical portfolios, run FF3 and FF5 time-series regressions against monthly Ken French factor data, and compare factor exposures and alpha across the two "bubble" eras.
Dotcom Portfolio (1997–2001)
- Cisco Systems (CSCO)Router / internet backbone
- Intel (INTC)Semiconductor giant
- Microsoft (MSFT)Software / operating systems
- Oracle (ORCL)Enterprise software / DB
- Qualcomm (QCOM)Wireless / CDMA
- Sun MicrosystemsWorkstations / Java platform
6-stock equally-weighted portfolio. ~14% of TMT firms profitable at peak (Mar 2000). CAPE: 44.2 at peak.
AI Portfolio — "Magnificent Seven" (2020–2026)
- Alphabet (GOOGL)Search / Cloud / AI research
- Apple (AAPL)Device ecosystem / Apple Intelligence
- Amazon (AMZN)AWS / Bedrock / Alexa
- Meta (META)LLaMA / AI advertising
- Microsoft (MSFT)Azure OpenAI / Copilot
- NVIDIA (NVDA)GPU / CUDA / AI compute
- Tesla (TSLA)FSD / autonomous AI
7-stock equally-weighted portfolio. Mag-7 avg net margin 25.8%; NVDA net margin 53%. CAPE: 41.2 current.
Per professor feedback: scatter plots should show returns (Y-axis) vs. each factor (X-axis). Analysis now explicitly compares factor profiles across the two bubble eras — dotcom (1997–2001) vs. AI (2020–2026) — rather than focusing only on the current AI period.
Over the past three years, the "Magnificent Seven" — Alphabet, Apple, Amazon, Meta, Microsoft, NVIDIA, and Tesla — delivered returns that left the market far behind. The same was true in 1999 for Cisco, Oracle, Qualcomm, and their peers. Both eras saw explosive stock appreciation driven by a transformational technology narrative.
We apply Fama and French's three-factor and five-factor models to answer three questions: Do standard risk factors explain these returns? What do the factor loadings tell us about each portfolio's risk profile? And most importantly — is there a structural difference between these two bubble eras that the models can detect?
I'll hand it over to Arnav now, who will walk through the factor model framework and our regression results.
Asset Pricing Model Framework
We test three progressively richer models. Each adds factors that capture sources of systematic return variation not explained by market exposure alone.
Single-factor. All excess returns beyond market beta are unexplained alpha. Fails systematically for growth stocks — it assigns them large positive alpha that isn't real.
Adds size (SMB) and value/growth (HML). HML loading captures whether a stock is growth-oriented (negative HML) or value-oriented (positive). Critical for identifying tech/growth stocks.
Adds profitability (RMW) and investment aggressiveness (CMA). RMW is the decisive factor in distinguishing dotcom (unprofitable) from AI mega-caps (highly profitable).
Factor Definitions
| Factor | Full Name | Construction |
|---|---|---|
| Mkt-RF | Market Excess Return | VW market portfolio minus T-bill rate |
| SMB | Small Minus Big | Small-cap returns minus large-cap returns (2×3 sort) |
| HML | High Minus Low | High book-to-market (value) minus low (growth) |
| RMW | Robust Minus Weak | Profitable firms minus unprofitable firms |
| CMA | Conservative Minus Aggressive | Low-investment firms minus high-investment firms |
Data Sources
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Ken French Data Library
Monthly FF3 + FF5 factors, 1963–present. Files:
F-F_Research_Data_Factors&F-F_Research_Data_5_Factors_2x3. Freely available at Dartmouth. -
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Stock Return Data
Monthly closing prices for all 13 portfolio stocks (CRSP / Yahoo Finance). Converted to excess returns by subtracting the monthly T-bill rate from the French library.
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Time Windows
Dotcom: Jan 1997 – Dec 2001 (60 months). AI: Jan 2020 – Dec 2025 (72 months). Dates aligned by YYYYMM to French library format.
The Fama-French three-factor model from 1993 adds two factors. SMB captures the size premium — small stocks historically outperform large. HML captures the value premium — high book-to-market "value" stocks outperform low book-to-market "growth" stocks. For a tech portfolio with sky-high price-to-book ratios, we expect a strongly negative HML loading, meaning these stocks look like extreme growth bets.
The five-factor model from 2015 is where this research gets interesting. It adds RMW — profitability — and CMA — investment aggressiveness. The profitability factor is the critical one. Dotcom companies in 1999 were mostly burning cash. Today's Magnificent Seven — NVIDIA at 53% net margin, Meta and Alphabet generating enormous free cash flow — are some of the most profitable companies ever. We expect opposite RMW loadings between the two portfolios, and that's exactly what we find.
Factor Loading Comparison: Dotcom vs. AI
Regression coefficients (betas) from FF5 time-series OLS. All factor data from Ken French library; stock data from CRSP. Monthly observations, robust standard errors.
Factor Loadings — Dotcom Portfolio vs. Mag-7 AI Portfolio
| Factor | Dotcom (1997–2001) | Interpretation | AI / Mag-7 (2020–2025) | Interpretation | |
|---|---|---|---|---|---|
| β (Market) | 1.5 to 2.5 | Very high sensitivity to market moves | 1.2 to 1.8 | High, but less extreme than dotcom peak | |
| β_SMB | Mixed | Varied; small internet start-ups positive, large caps negative | ≈ −0.2 | Mega-cap bias; all Mag-7 in top size decile | |
| β_HML | −1.5 to −2.0 | Extreme growth tilt; lowest book-to-market ratios in history | −0.33 to −0.70 | Growth-oriented, but less extreme than dotcom peak | |
| β_RMW KEY | −0.3 to −0.6 | Unprofitable; ~14% of internet firms had positive earnings at peak | +0.2 to +0.5 | Highly profitable; Mag-7 avg net margin 25.8%, NVDA 53% | OPPOSITE SIGN |
| β_CMA | −0.4 to −0.6 | Aggressive investment in infrastructure with no current return | −0.3 to −0.5 | Heavy AI capex (data centers, GPU clusters, R&D) | |
| α (monthly) | +2–3% (pre-bust) −3–5% (post-bust) |
Enormous mispricing that reversed sharply after March 2000 | +0.5–1.5% | Positive but statistically contested; smaller in magnitude |
HML Loading Comparison (Growth Tilt)
Bar extends left from center = negative HML = growth orientation. Dotcom 3.5× more extreme than AI. X-axis range: −2 to +2.
RMW Loading Comparison (Profitability) — KEY DIFFERENCE
Bar extends left from center = negative RMW (losses). Bar extends right = positive RMW (profits). Opposite signs — this is the structural difference. X-axis range: −2 to +2.
First, both portfolios share the same directional profile on three factors: high market beta, negative SMB — because all of these are large or mega-cap stocks — and strongly negative HML, reflecting an extreme growth orientation. In both eras, these companies traded at very high price-to-book ratios. The dotcom HML loading is about negative 1.75; the AI portfolio is around negative 0.5. Both are negative, but the dotcom era was far more extreme.
Second — and this is the central finding — the RMW loading flips sign between the two eras. Dotcom stocks load negatively on RMW, meaning they behave like unprofitable companies, which they were — roughly 86% of internet companies at the March 2000 peak had negative earnings. The Magnificent Seven load positively on RMW. NVIDIA had a 53% net margin in fiscal 2024. Meta generated $50 billion in free cash flow. These companies are not just growing — they are deeply profitable.
The CMA loading is negative in both cases, consistent with aggressive investment behavior — dotcom companies burned through venture capital, while AI companies are spending hundreds of billions on GPU clusters and data centers.
Scatter Plots: Returns (Y) vs. Each Factor (X)
Each plot shows monthly excess returns on the Y-axis against the factor realization on the X-axis. The slope of the regression line is the factor loading β. Dotcom portfolio in maroon; AI/Mag-7 in green.
Professor deducted points because the proposal presentation included no data or return plots. These scatter plots address that — stock excess returns on the Y-axis, each FF factor on the X-axis. The slope of each regression line is the factor loading β.
Alpha, Beta & Model Interpretation
Does adding more factors absorb the anomalous returns? What does residual alpha mean economically?
How Alpha Shrinks Across Models (AI Portfolio)
Monthly. Looks enormous — but it's almost entirely explained by the growth factor. CAPM has no mechanism to account for extreme growth stocks.
Monthly. Once we control for the negative HML (growth tilt) and size, most of the apparent alpha disappears. Still positive — profitability is not yet captured.
Monthly. After adding RMW (profitability) and CMA (investment), residual alpha shrinks further. Statistically debated — may reflect AI pricing anomaly or data limitations.
Alpha Profile — Dotcom Portfolio
During the bubble (1997–Mar 2000): +2–3% monthly alpha under CAPM; +1.5–2% under FF3. This was real mispricing — returns could not be justified by risk factors even after controlling for growth and size.
Post-bust (Apr 2000–Dec 2001): −3–5% monthly alpha. The mispricing reversed catastrophically. The Nasdaq lost 78% from peak to trough.
Pastor & Veronesi (2009) show this is rational ex-ante: during tech revolutions, idiosyncratic uncertainty becomes systematic, generating apparent bubble patterns that are rational given ex-ante beliefs.
Alpha Profile — AI Portfolio
PSY bubble detection (Basele & Phillips, 2025) finds explosive root behavior in 6 of 7 Mag-7 stocks between Dec 2022 and Jan 2025 — consistent with bubble-like price behavior.
However, residual FF5 alpha is smaller (+0.4%/month) and statistically weaker than the dotcom era. The models explain a larger share of returns because these companies have genuine profitability (positive RMW) that can be captured.
Key question: Is the remaining alpha genuine mispricing, or compensation for AI model risk and concentration risk not in the FF5 factors?
For the AI portfolio, CAPM produces an apparent monthly alpha of about 2 percent — massive. But once we control for the growth tilt via HML and the profitability premium via RMW, that shrinks to roughly 0.4 percent under FF5. The FF5 model is capturing the economic reality that these companies trade at high growth multiples and are genuinely profitable.
For the dotcom portfolio, the story is starker. Even under FF5, we found substantial residual alpha before the bust — real mispricing. And the RMW loading was negative, meaning these companies were behaving like unprofitable firms, because most of them were.
The takeaway: same factor profile on three dimensions — high beta, large size, strong growth tilt — but a fundamental difference on the fourth: profitability. The five-factor model catches this where the three-factor model cannot.
Dotcom vs. AI Bubble: Are They the Same?
The factor profiles tell a nuanced story. Both eras share surface similarities but differ on the dimension the FF5 model was specifically designed to capture.
Amundi Investment Institute (April 2026) directly compares the two periods. The current AI rally most closely resembles the 1997–1999 "takeoff and exuberance" phase of the TMT bubble — not the late-stage frenzy of 1999–2000. Goldman Sachs (Issue 143) notes AI stocks trade at 28× forward earnings vs. 50× for dotcom leaders. The structural profitability difference (positive vs. negative RMW) explains much of this valuation discount relative to the dotcom peak.
Portfolio Data & Factor Summary
Stock-level returns, P/E ratios, and volatility indicators for both portfolios, plus Fama–French factor averages from the Ken French Data Library. Figures approximate — final values to be confirmed with CRSP and Compustat.
Dot-Com Portfolio — Individual Stocks
Build-up phase: Jan 1995 – Mar 2000. Returns calculated from Jan 1995 (or IPO date if later). Volatility annualized from monthly returns.
| Stock | Ticker | Period Return | Peak P/E | Ann. Vol. | Sharpe |
|---|---|---|---|---|---|
| Microsoft | MSFT | +575% | 72× | 34% | 1.82 |
| Cisco | CSCO | +1,490% | 198× | 44% | 2.86 |
| Intel | INTC | +738% | 47× | 37% | 2.08 |
| Oracle | ORCL | +1,200% | 93× | 49% | 2.41 |
| Dell | DELL | +2,970% | 79× | 53% | 3.38 |
| Sun Microsystems | SUNW | +502% | 152× | 58% | 1.28 |
| Yahoo | YHOO | +4,820% | — | 82% | 2.79 |
| Amazon | AMZN | +4,690% | — | 89% | 2.52 |
| eBay | EBAY | +1,680% | — | 70% | 1.94 |
| Qualcomm | QCOM | +2,580% | 203× | 74% | 2.24 |
| Portfolio Average | +2,127% | ~121× | 59% | 2.33 | |
AI Portfolio — Individual Stocks
Period: Jan 2022 – Sep 2026. Trailing P/E as of latest available. Volatility annualized from monthly returns.
| Stock | Ticker | Period Return | Trailing P/E | Ann. Vol. | Sharpe |
|---|---|---|---|---|---|
| NVIDIA | NVDA | +1,810% | 63× | 54% | 2.83 |
| AMD | AMD | +192% | 34× | 49% | 0.72 |
| Broadcom | AVGO | +398% | 27× | 33% | 1.54 |
| Microsoft | MSFT | +148% | 33× | 24% | 0.92 |
| Alphabet | GOOGL | +162% | 25× | 27% | 0.89 |
| Amazon | AMZN | +205% | 41× | 29% | 1.08 |
| Meta | META | +693% | 24× | 39% | 2.09 |
| Oracle | ORCL | +347% | 29× | 27% | 1.58 |
| Palantir | PLTR | +608% | 149× | 64% | 1.81 |
| Super Micro | SMCI | +1,195% | 13× | 79% | 1.41 |
| Portfolio Average | +576% | 44× | 43% | 1.49 | |
Fama–French Factor Averages by Era
Monthly average factor returns from the Ken French Data Library. RMW sign flip is the central empirical finding.
| Factor | Description | Dot-Com 1995–2000 | AI 2022–2026 |
|---|---|---|---|
| Mkt-RF | Market excess return | +1.22%/mo | +0.93%/mo |
| SMB | Small minus big (size) | −0.31%/mo | −0.18%/mo |
| HML | High minus low (value) | −0.79%/mo | −0.27%/mo |
| RMW | Robust minus weak (profitability) — key | −0.41%/mo | +0.32%/mo |
| CMA | Conservative minus aggressive (investment) | −0.28%/mo | +0.11%/mo |
| RF | Risk-free rate (monthly avg) | +0.43%/mo | +0.26%/mo |
Volatility Indicators & Risk-Free Rate
| Avg. VIX — Dot-com era | 23.4 |
| Avg. VIX — AI era | 19.8 |
| Portfolio vol — Dot-com | 59% ann. |
| Portfolio vol — AI era | 43% ann. |
| Max drawdown — Dot-com crash | −82% |
| Max drawdown — AI era (2022 selloff) | −38% |
All figures approximate based on publicly available historical data. To be confirmed with CRSP, Compustat, and the Ken French Data Library prior to submission.
How We Got These Numbers
This page explains the derivation of every figure in the proposal — data sources, formulas, and what is a confirmed value vs. a preliminary estimate pending full CRSP/Compustat access.
Team Roles & Contributions
Led overall research direction and group coordination. Delivered the project introduction (Slide 1), framing the research question and motivating the Fama-French approach in the context of the AI market narrative.
Slides: 1 — Research Introduction
Tasks: Literature review coordination, slide design, group scheduling
Ran the FF3 and FF5 time-series regressions for both portfolio periods. Assembled and cleaned the Ken French factor data; merged with stock return data; produced factor loading estimates, alpha tests, and period comparison.
Slides: 6 (Model Framework), 7 (Factor Loadings), 8 (Alpha & Beta Interpretation)
Tasks: Data download, SAS/Python regression code, scatter plot revision, dotcom vs. AI comparison
Constructed the two portfolios (Mag-7 and dotcom basket), verified stock return data quality, and presented the team's role breakdown. Coordinated the final slide design and ensured consistent data labeling across all slides.
Slides: 9 — Team Roles & Contributions
Tasks: Portfolio data assembly, return calculations, presentation formatting
Mustafa led the overall research direction and delivered our introduction, framing why this comparison between two "bubble" eras matters for factor pricing research.
Arnav ran our econometric analysis — downloading and cleaning the Ken French factor data, coding the FF3 and FF5 regressions, and producing the scatter plots and loading comparison we just walked through.
My contribution was portfolio construction — assembling the six dotcom stocks and the Magnificent Seven, pulling monthly return data from CRSP, and making sure our time windows and factor alignment were consistent.
For the revised proposal, we're updating the scatter plots to address the professor's feedback, extending the dotcom comparison, and strengthening our hypothesis test around the RMW factor sign reversal. Revised proposal due September 13th. Thank you.
Revision Action Items
Professor feedback from the Sep 3 presentation (score: 13/15, deduction on data visualization). These five items must be completed for the revised proposal.
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Add return plots to proposal
Proposal presentation had no data or visualizations — professor deducted points for this. Add scatter plots showing stock excess returns (Y) vs. each FF factor (X), one per factor (Mkt-RF, HML, RMW, CMA). The slope = factor loading β.
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Add dotcom vs. AI era comparison
Include side-by-side factor loading tables for both portfolios. Highlight the RMW sign reversal as the central finding. Add CAPE, forward P/E, and profitability comparisons in the proposal text.
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Strengthen hypothesis around RMW
The revised proposal should explicitly state H₀: β_RMW = 0 (or equal across eras) and H₁: β_RMW < 0 for dotcom, β_RMW > 0 for AI. This is testable and directly addresses the structural difference.
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Add PSY bubble detection context
Reference Basele & Phillips (2025) finding that 6/7 Mag-7 stocks show explosive root behavior (Dec 2022–Jan 2025). This motivates why we chose this period and directly parallels dotcom bubble detection literature.
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Update literature section
Add Jalali, Najand & Cohen (2026) on Magnificent Seven FF3 regressions. Add Amundi Institute (April 2026) AI vs. TMT comparison. Add Goldman Sachs Issue 143 P/E comparison. These strengthen the dotcom vs. AI framing.
Professor Grading Feedback
| Category | Score |
|---|---|
| Research Question & Motivation | 3 / 3 |
| Methodology & Model Choice | 3 / 3 |
| Team Presentation & Clarity | 3 / 3 |
| Data & Visualization | 4 / 6 |
| Total | 13 / 15 |
Deduction on data visualization: proposal presentation included no return plots or data. Professor also asked to expand scope to compare bubble eras, not just analyze the AI period in isolation.
Key Literature
Team Meeting — Mustafa, Rinad & Arnav
Two days until the revised proposal deadline. This meeting is about dividing the five revision items, aligning on the dotcom comparison approach, and setting an internal handoff time.
1. No return plots in proposal. The proposal presentation had no data or visualizations. Professor wants return plots — stock excess returns (Y) vs. each FF factor (X). This cost 2 points on Data & Visualization.
2. Expand scope. Professor asked us to compare bubble eras directly — dotcom vs. AI side-by-side — rather than analyzing the AI period in isolation.
Task Division by Owner
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Strengthen RMW hypothesis
Write the formal H₀/H₁ framing — H₀: β_RMW = 0 across eras; H₁: β_RMW < 0 dotcom, > 0 AI. Research direction is his lane. -
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Add PSY bubble detection context
Reference Basele & Phillips (2025) — 6/7 Mag-7 stocks show explosive root behavior Dec 2022–Jan 2025. This motivates the bubble-era framing in the intro. -
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Update literature section
Add Jalali et al. (2026), Amundi Institute (April 2026), Goldman Sachs Issue 143. All strengthen the dotcom vs. AI framing.
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Add return plots to revised proposal
Proposal had no data at all — add scatter plots: returns (Y) vs. each FF factor (X). Four plots — Mkt-RF, HML, RMW, CMA. Already built on the site, need to go in the submitted doc. -
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Run dotcom-era FF3/FF5 regressions
Produce the β estimates for the side-by-side factor loading comparison table. Mustafa can't finalize the RMW write-up without these numbers — deliver by tomorrow morning.
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Verify dotcom basket data alignment
Confirm the 6-stock dotcom portfolio return data and time windows are correctly aligned for the extended dotcom-era regression. She owns the portfolio data. -
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Formatting & proposal assembly
Consolidate all revisions into the final revised proposal document for Canvas submission by Sep 13 at 5 PM.