Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

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US · SEC FORM 4

DEXCOM INC

DXCM · Nasdaq · CIK 0001093557 · Healthcare · Medical Devices

INSIDER SIGNAL

No active buy signal

0 qualifying P purchase groups
in the current 180-day scoring window

49 Form 4 transaction lines observed in the same window
24 sales · 25 option, withholding, award, gift or other lines

Last qualifying purchase2025-11-10 · Leach Jacob Steven · $1.0M

WHY NO ACTIVE SIGNAL?

Purchase activityNone
Recent buyingNone
Recent salesHigh
Buy signal statusInactive
Score anatomy

No score is calculated because there is no qualifying purchase in the active window. Unavailable inputs are not treated as zero or as a bearish signal.

ClusterNot calculated
Purchase sizeNot calculated
RoleNot calculated
RecencyNot calculated
ConvictionNot calculated

Why is there no score?

  • No qualifying open-market purchase supplies cluster, size, role, recency or conviction inputs.
  • Sales and other Form 4 activity remain visible as context and do not create a negative score.

Sales and other Form 4 activity are shown separately and do not create a negative buy signal. Absence of buying is not scored as bearish.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
Brown Michael JonEVP Chief Legal Compliance Off
▼○▼▼▼○▼
FOLETTA MARK GDirector
○○▼▼▼
AUGUSTINOS NICHOLASDirector
○○○▼▼
Stern SadieEVP Chief People & Culture Off
○○▼▼
SAYER KEVIN RExecutive Chair
▼▼▼▼
Coleman JonEVP, Chief Commercial Officer
○▼▼
● Purchase▼ Sale○ Other

Showing the six most active owners; 11 additional owner(s) remain in Form 4 evidence.

Purchase breadth, concentration & cluster buying

These modules activate when qualifying purchases enter the 180-day research window.

SIGNAL HISTORY

No recorded active-signal snapshot

Scores are archived only when the company qualifies for a published US buy-signal snapshot. Last qualifying purchase: 2025-11-10 · Leach Jacob Steven.

Recent Form 4 activity

2Purchases
30Sales
48Other Form 4 lines
63SEC filings · 365 days
BUYING0 qualifying P line(s) · 180 days
SELLING24 sale line(s) · context only
OTHER25 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context has not been captured for this ticker yet. The daily market-context job processes the US universe in rotating batches.

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
14,017,639
Previous report
17,263,625
Avg daily volume
4,440,324
Days to cover
3.2

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2025-11-10Leach Jacob StevenPurchase (P)Common Stock18,200USD 55.04USD 1,001,761SEC filing ↗

Form 4 evidence

80 transaction lines in the latest 365-day window; 1,250 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-28Stern SadieSale (S)Common Stock2,565USD 86.15USD 220,975SEC filing ↗
2026-09-15Brown Michael JonSale (S)Common Stock1,700USD 84.04USD 142,868SEC filing ↗
2026-09-15AUGUSTINOS NICHOLASSale (S)Common Stock6,539USD 84.04USD 549,538SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-28Stern SadieSale (S)Common Stock2,565USD 86.15USD 220,975SEC filing ↗
2026-09-15Brown Michael JonSale (S)Common Stock1,700USD 84.04USD 142,868SEC filing ↗
2026-09-15AUGUSTINOS NICHOLASSale (S)Common Stock6,539USD 84.04USD 549,538SEC filing ↗
2026-09-14AUGUSTINOS NICHOLASSale (S)Common Stock1,550USD 84.02USD 130,231SEC filing ↗
2026-09-10Sylvain Jereme MSale (S)Common Stock3,638USD 83.27USD 302,936SEC filing ↗
2026-09-10Boehnlein Glenn SAward / grant (A)Common Stock5,841USD 0.00USD 0SEC filing ↗
2026-08-27Stern SadieSale (S)Common Stock2,565USD 88.37USD 226,669SEC filing ↗
2026-08-22Sylvain Jereme MTax withholding (F)Common Stock1,451USD 92.34USD 133,985SEC filing ↗
2026-08-22Stern SadieTax withholding (F)Common Stock1,451USD 92.34USD 133,985SEC filing ↗
2026-08-22Leach Jacob StevenTax withholding (F)Common Stock1,451USD 92.34USD 133,985SEC filing ↗
2026-08-22Brown Michael JonTax withholding (F)Common Stock1,451USD 92.34USD 133,985SEC filing ↗
2026-08-20SAYER KEVIN RSale (S)Common Stock26,756USD 90.01USD 2,408,311SEC filing ↗
2026-08-14Brown Michael JonSale (S)Common Stock1,700USD 91.93USD 156,281SEC filing ↗
2026-08-12Heller Bridgette PSale (S)Common Stock1,012USD 88.29USD 89,349SEC filing ↗
2026-08-12AUGUSTINOS NICHOLASGift (G)Common Stock1,075USD 0.00USD 0SEC filing ↗
2026-08-03FOLETTA MARK GSale (S)Common Stock2,000USD 85.32USD 170,640SEC filing ↗
2026-07-31FOLETTA MARK GSale (S)Common Stock2,000USD 80.00USD 160,000SEC filing ↗
2026-07-20SAYER KEVIN RSale (S)Common Stock26,756USD 76.32USD 2,042,018SEC filing ↗
2026-07-15Brown Michael JonSale (S)Common Stock1,700USD 74.42USD 126,514SEC filing ↗
2026-07-06SAYER KEVIN RSale (S)Common Stock26,756USD 72.00USD 1,926,432SEC filing ↗
2026-06-15FOLETTA MARK GSale (S)Common Stock4,000USD 74.14USD 296,543SEC filing ↗
2026-06-15Brown Michael JonSale (S)Common Stock1,700USD 75.55USD 128,435SEC filing ↗
2026-06-04Coleman JonSale (S)Common Stock4,911USD 74.13USD 364,052SEC filing ↗
2026-06-03Coleman JonSale (S)Common Stock4,912USD 73.00USD 358,576SEC filing ↗
2026-05-28Osterloh Albert Frederick IVAward / grant (A)Common Stock1,630USD 0.00USD 0SEC filing ↗
2026-05-28Malady KyleAward / grant (A)Common Stock5,575USD 0.00USD 0SEC filing ↗
2026-05-28Heller Bridgette PAward / grant (A)Common Stock5,575USD 0.00USD 0SEC filing ↗
2026-05-28GALA RENEE DAward / grant (A)Common Stock5,605USD 0.00USD 0SEC filing ↗
2026-05-28FOLETTA MARK GAward / grant (A)Common Stock6,331USD 0.00USD 0SEC filing ↗
2026-05-28Driscoll RimmaAward / grant (A)Common Stock5,605USD 0.00USD 0SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerDXCM
CIK0001093557
SectorHealthcare
IndustryMedical Devices Yahoo Finance
SEC SIC3841 Surgical & Medical Instruments & Apparatus
ExchangeNasdaq

Data coverage

Local Form 4 history1,250 transaction lines from 2020-01-02 to 2026-09-28
2 P purchase lines · 900 S sale lines · 348 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.