DexCom (DXCM): Revenue Rose $151M And Cost Of Sales Rose $10M. Is DXCM a Buy?

DexCom, Inc. (DXCM) Q2 2026 — Reported after the close July 30, 2026 (quarter ended June 30). Revenue $1,308.4M, +13.1% reported and +12% organic. US $933.4M (+11.0%); international $375.0M (+18.6%). GAAP operating margin 24.3% vs 18.4% — operating income +49.7%. GAAP diluted EPS $0.64 (+42%); non-GAAP $0.70 (+46%). Adjusted EBITDA $421.3M, 32.2% of revenue. FY26 revenue guidance raised at the midpoint to $5.18-5.25B, with gross margin, operating margin and EBITDA margin guidance all raised. The stock closed +11.95% the next session at $83.45 — a new 12-month closing high. The framing nobody applied: revenue rose $151.3M year over year and cost of sales rose $10.1M. That is a 93% incremental gross margin, and it is why operating income grew 49.7% on 13.1% revenue growth. Second unwritten line: the effective tax rate fell from 25.4% to 21.5% because the Malaysia tax holiday commenced. Two structural changes, one factory, neither in the headline. THE CALL: HOLD (4/5, A REAL INFLECTION, AND A PRICE THAT ALREADY OWNS IT) — base-case value ~$83.0 vs ~$83.45 today. KEY METRICS: - CALL: HOLD 4/5 — fair value ~$83 vs $83.45 (-0.5%). FY2026 free cash flow base ~$1.0B (guided $5.215B revenue at the guided 31.75% adjusted EBITDA margin = $1.656B, less ~$285M cash tax at the new 21.5% rate, less ~$340M capex with Ireland starting up; H1 already delivered $633.5M). DCF at 14% for five years then 8%, 2.5% terminal, 9.0% discount = $30.7B EV plus $704M net cash / 380M diluted shares = $83. Probability-weight the column 25/50/25 and you get $82. - THE COST LINE IS THE STORY: revenue +$151.3M ($1,157.1M to $1,308.4M) while cost of sales rose just $10.1M ($468.3M to $478.4M, +2.2%). Gross profit +$141.2M — a 93% incremental gross margin. Across H1: revenue +$307.2M, cost of sales +$4.7M. GAAP gross margin 59.5% to 63.4%; non-GAAP 60.1% to 64.1%. The 10-Q names the driver: G7 15-Day benefits, manufacturing efficiencies, higher production volumes and 'better absorption of fixed costs'. The 2024-25 margin collapse was overhead against too few units, not price. - THE TAX LINE NOBODY READ: effective tax rate 21.5% vs 25.4%, 'primarily attributable to the commencement of our Malaysia tax holiday'. Tax was $68.4M on $317.5M pre-tax; at the old rate it would have been ~$80.6M, so the holiday was worth ~$12M — about $0.03 of the $0.19 GAAP EPS increase. A manufacturing tax holiday runs for years, on the same plant whose fixed costs just started absorbing. The offset: other income went +$28.5M to -$0.8M (-$11.1M interest income, -$10.3M FX, -$9.6M equity losses), so pre-tax income grew 31.7% against 49.7% for operating income. - THE HONEST BEAR CASE: the RAISED full-year midpoint of $5.215B against H1 of $2,500.3M implies $2,714.7M in H2 versus $2,468.9M a year ago — about +10%, against +14.0% in H1. Only ~$15M of that is the flagged FX headwind. And Q2 operating cash flow FELL 11% to $269.2M even as operating income rose 50%, on a $101.6M H1 inventory build ($629.1M to $726.4M) ahead of Ireland and the 15-day conversion. - GLP-1 AND CASH: in the CONNECT randomised trial, type 2 non-insulin patients on DexCom improved A1C 1.6% over six months (0.9% vs control) with 97% median wear — and management stated the LARGEST relative A1C improvement was in the cohort using GLP-1 therapies ALONE. H1 free cash flow $633.5M vs $305.7M ($794.8M operating cash less $161.3M capex, capex DOWN 11%). $600.0M of buyback in Q2 (8.6M shares) out of a new $1.00B authorisation; diluted shares 408.2M to 390.1M. Street: Buy, $89.23 consensus (+6.9%), range $64-$105 — we ALIGN on the business, CAUTIOUS on price. What to watch: Bullish: a positive CMS decision on type 2 non-insulin coverage before year end (25 million Americans, roughly half of Medicare age); the G7 15-Day conversion passing 50% of the US base by year end, which becomes the 2027 starting point; second-half non-GAAP gross margin holding above 64% through the Ireland start-up. Bearish: second-half revenue growth below 10% on the Oct 29 print, which would turn the guide from conservatism into real deceleration; a second consecutive quarter of falling operating cash flow, which would say the $101.6M inventory build is demand and not preparation; or the US direct line, already down 2.7%, turning out to be the leading edge of price competition. Also on YouTube: @ChargedAlpha DISCLAIMER: For informational and educational purposes only. Not financial advice. Do your own research before any investment decision.