AA vs QTTB: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. AA and QTTB share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined AA and QTTB exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Alcoa Corporation is one of the world's largest upstream aluminum companies, running the full chain from bauxite mining to alumina refining to aluminum smelting. It reports in two segments: Alumina (roughly 2.4 million metric tons produced in Q1 2026) and Aluminum (about 607,000 metric tons in the same quarter). Because it sells raw and semi-finished metal into global markets, Alcoa is a price-taker: its revenue and margins are driven mainly by the London Metal Exchange aluminum price and the alumina price index, plus its own energy and raw-material costs. That makes it different from downstream fabricators like Arconic that sell finished, engineered products at steadier margins.

Full AA guide

Q32 Bio Inc. is a clinical-stage biotechnology company focused on alopecia areata (AA) and other autoimmune and inflammatory diseases. Its lead and effectively only clinical program is bempikibart (ADX-914), a fully human monoclonal antibody that blocks the interleukin-7 receptor alpha chain and therefore shuts down signaling from both IL-7 and TSLP, two pathways implicated in the T-cell attack on hair follicles. The company reached the public market by reverse-merging into Homology Medicines in March 2024, which is why the CIK on EDGAR still carries the old FIXX ticker, and it trades on the Nasdaq Capital Market with about 24 employees under CEO Jodie Morrison. Its history since then has been a sequence of narrowing decisions: bempikibart missed in atopic dermatitis (the SIGNAL-AD trial, topline December 2024), the company restructured in February 2025 to focus on AA, and in November 2025 it sold the entire ADX-097 complement program to Akebia Therapeutics. What remains is bempikibart, a preclinical half-life-extended follow-on called ADX-914-XL, and a retained tissue-targeted complement platform (ADX-096 and related molecules) that management describes as under strategic review.

Full QTTB guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• AA drivers: Aluminum price and supply gap; San Ciprian restart and higher volumes.
• QTTB drivers: Bempikibart and the path to a registration-directed program; A balance sheet that now outlasts the next trial.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The dominant risk is commodity price cyclicality: with revenue tied to aluminum and alumina indices, a global slowdown or a swing in Chinese supply can compress earnings quickly, as Q1 2026's weaker alumina pricing already showed. For QTTB, the concentration risk is total: one unpartnered asset, one indication, and a company that already watched bempikibart fail to earn a path forward in atopic dermatitis before it restructured around AA in February 2025.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick AA if you believe its drivers more; QTTB if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the AA and QTTB guides.

AA. Figures are approximate and tied to the asOf date; verify live numbers before acting. For a cyclical producer, a low forward P/E can be a trap because it reflects peak-cycle earnings that may not repeat if metal prices fall, so earnings multiples on Alcoa mean less than where aluminum prices sit in the cycle. Analyst targets skew bullish on the aluminum supply-gap thesis, but that view is a bet on the commodity as much as on the company.

QTTB. Figures are approximate, tied to August 2026 and drawn from the Q2 2026 10-Q filed August 5, 2026 and the fiscal 2025 10-K, so check live data before acting on any of them. Two screen-level numbers on QTTB are misleading and worth discarding: the ~5.3x trailing P/E and the ~8.8x price-to-sales both derive from the ~$53.7 million of one-time non-cash collaboration revenue and the ~$29.8 million of 2025 net income it produced, and neither describes an operating business. The number that carries information is enterprise value, roughly ~$276 million once the ~$294 million of pro forma cash is netted against the fully-funded equity value, which is what the market is assigning to bempikibart, the retained complement platform and the Akebia royalty stream combined.

Headline figures (approximate, July 2026): AA shows revenue (ttm) ~$13 billion (Q1 2026 was ~$3.19 billion, down ~5% year over year), net income (q1 2026) ~$425 million attributable to common shareholders, diluted eps (q1 2026) ~$1.60 (adjusted ~$1.40), market cap ~$12.4 billion (stock ~$47 per share); QTTB shows revenue (ttm) ~$53.7 million, all of it recognized in the fourth quarter of 2025 and none of it product revenue: it is the derecognition of a ~$55.0 million refund liability from the terminated Horizon collaboration, settled with Amgen on November 7, 2025 for ~553,695 shares. Revenue in the first half of 2026 was ~$0, loss rate Net loss of ~$8.9 million in Q2 2026 and ~$16.6 million for the first half, on operating expenses of ~$16.8 million (R&D ~$7.5 million, G&A ~$9.4 million); net cash used in operations was ~$9.4 million for the half versus ~$23.1 million a year earlier. Accumulated deficit stands at ~$221.5 million, cash and runway ~$106.3 million of cash and equivalents at June 30, 2026, plus ~$187.6 million net from the July 16 follow-on, for roughly ~$294 million before third-quarter spending. Management states this funds operations through topline Phase 3 results of the planned registration-directed program, and explicitly not through regulatory approval, balance sheet Total assets ~$115.9 million against total liabilities ~$10.0 million and stockholders' equity ~$105.9 million at June 30, 2026, all before the July raise. Debt-free since the ~$6.8 million Silicon Valley Bank venture-debt payoff on June 24, 2026.

AA and QTTB are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined AA and QTTB exposure against your real portfolio. It is not an investment adviser.