Rambus (RMBS): Record Quarter, Stock Down 51% — Bargain or Still Priced for Perfection?

Rambus Inc. (RMBS) Q2 2026 — Rambus (RMBS), the memory-interface chip and silicon-IP company that sits between the processor and the memory in every AI server, reported Q2 2026 (quarter ended June 30, 2026) after the close on July 27: record revenue of $207.4M (+20% YoY), above its own $192-198M guide; record product revenue of $99.2M (+22% YoY, +13% QoQ); royalties $84.3M (+23%); contract & other $24.0M (+8%). Non-GAAP diluted EPS $0.77 beat the ~$0.73 consensus; GAAP diluted EPS was $0.61. Operating cash flow $61.2M; cash and marketable securities $824.9M with zero debt (~$7.50/share of net cash). But underneath the records: GAAP operating margin FELL from 36.6% to 35.1% on +20% revenue, SG&A rose 36% versus revenue +20%, and Rambus booked a $3.3M restructuring charge plus facility-closure costs. The Q3 guide (revenue $210-216M) has product revenue rising to $110-116M while royalties — the ~100%-incremental-margin line — are guided DOWN to $69-75M, roughly -15% sequentially; licensing billings of $84.1M essentially matched reported royalty revenue and deferred revenue fell from $30.0M to $21.2M, so there is no deferred cash cushion. Stock-based comp was $15.9M, 7.7% of revenue, making non-GAAP EPS 26% higher than GAAP; Rambus repurchased zero shares in the quarter while the stock fell from $170 to $123, and insiders sold 25 times in six months with zero purchases. The company also disclosed in its Q1 2026 10-Q that it is responding to a federal grand jury subpoena in a criminal DOJ antitrust investigation. Our owner-earnings DCF — expensing stock comp honestly rather than using the non-GAAP figure, and adding back the $824.9M of net cash — lands fair value near $72 versus ~$83.21 today. Reverse-DCF: the current price requires ~20% owner-earnings growth per year for five straight years. Our call: AVOID, 3/5 — a great business, still about 13% above our fair value. Wall Street is Buy (11 buy / 3 hold / 0 sell, 14 analysts) with a $147.40 average target implying +77%, so we DIFFER sharply — and note most of those targets are dated April 28, 2026, before the 51% drawdown. Rambus (RMBS) just delivered the best quarter in its history and the stock fell 14% in two sessions, capping a 51% collapse from its June 3 peak of $170.66 to roughly $83.21 today. Rambus makes the register clock drivers and companion chips that sit on DDR5 memory modules — the bottleneck every AI server is choking on — and licenses memory-interface and security IP. Q2 2026 (ended June 30): record revenue $207.4M (+20% YoY, above the $192-198M guide), record product revenue $99.2M (+22%), royalties $84.3M (+23%), contract & other $24.0M. Non-GAAP EPS $0.77 beat ~$0.73; GAAP EPS was $0.61. Cash and securities $824.9M with zero debt, and $61.2M of operating cash flow. So why the sell-off? Three things the headline buries. First, GAAP operating margin FELL from 36.6% to 35.1% on 20% revenue growth — negative operating leverage in a record quarter — as SG&A jumped 36% and the company took its first restructuring charge in years. Second, the Q3 guide has the near-100%-incremental-margin royalty line guided DOWN about 15% sequentially to $69-75M while lower-margin (~60% GM) product chips rise to $110-116M: Rambus is deliberately swapping hundred-cent dollars for sixty-cent dollars. Licensing billings of $84.1M essentially matched reported royalty revenue and deferred revenue fell from $30.0M to $21.2M, so there is no hidden deferred cushion — $84M was the peak, not the run rate. Third, stock-based comp of $15.9M is 7.7% of revenue, making non-GAAP EPS 26% flatter than GAAP, diluted shares still rose 1.4%, and Rambus repurchased ZERO stock while it fell from $170 to $123 — with insiders selling 25 times in six months and buying nothing. Add an open criminal DOJ antitrust grand jury subpoena disclosed in the Q1 10-Q. Our owner-earnings DCF (free cash flow less stock comp, plus the $824.9M net cash back) lands near $72 a share; run backwards, today's $83.21 requires ~20% owner-earnings growth for five straight years, versus the 15% operating-income growth just delivered in the best quarter ever. Our call: AVOID, 3/5 — the crash took RMBS from absurd to merely expensive, and 'less overvalued' is not 'cheap.' We get interested below $72 and want it in the low $60s. Wall Street says Buy with a $147.40 average target (+77%), but most of those targets are dated April 28, 2026 — pre-crash — so we DIFFER, materially more cautious. Watch royalties and licensing billings every quarter. Not financial advice. THE CALL: AVOID (3/5, A GREAT BUSINESS STILL PRICED FOR 20% GROWTH — WE WANT IT BELOW $72, IDEALLY IN THE LOW $60s) — base-case value ~$72.00 vs ~$83.21 today. What to watch: royalty revenue stabilising above $80M a quarter instead of sliding, SG&A growth falling back below revenue growth, and management finally using the $824.9M of idle net cash to repurchase stock after a 51% drawdown would move us to a constructive call and likely an upgrade; the risks to respect are the opposite — further mix shift from ~100%-margin royalties into ~60%-margin product chips compressing operating margin, stock-based compensation staying above 7% of revenue while the share count rises, and an adverse outcome in the Department of Justice criminal antitrust investigation into the licensing model, which is the one tail risk that would genuinely impair the franchise rather than just the multiple Also on YouTube: @ChargedAlpha DISCLAIMER: For informational and educational purposes only. Not financial advice. Do your own research before any investment decision.