MarketPeel
Insider Trading Intelligence
Pricing
…
TG

Thomas J. Gunderson

MMSI
DIRECTOR · MERIT MEDICAL SYSTEMS INC · CIK 0001708144
FILING MIX · LIFETIME72%/28%
BUYS
21
SELLS
8
TOTAL VALUE
$6.66M
COMPANIES
2
ACTIVE SINCE
Jun 2020
HOLDINGS NOW
16,642
AVG SELL PX
$83.35
TRADE KIND
SHOWING 29 / 29
Trades · vs SPY
Loading price series…
Performance · forward returns vs SPY
1 backtested trades · 8 horizonsHow are these numbers computed? →
Forward-return performance of every backtestable P/S trade by Thomas J. Gunderson, measured at 8 horizons from 7 days to 2 years. Deduped per economic event so co-filings count once. Excess return = trade return minus SPY return over the same window.
HORIZONTRADESWIN RATEINSIDER RETURNSPY RETURNMEAN EXCESSMEDIAN EXCESST-STAT
7d1+100.00%-2.48%-0.20%-2.28%-2.28%—
14d1+100.00%-5.63%+0.42%-6.05%-6.05%—
30d1+100.00%-4.78%+1.70%-6.49%-6.49%—
60d1+0.00%+3.21%+0.11%+3.10%+3.10%—
90d1+0.00%+7.41%+3.35%+4.07%+4.07%—
180d1+0.00%+26.36%+10.73%+15.63%+15.63%—
1y1+0.00%+33.17%+14.05%+19.13%+19.13%—
2y1+100.00%-3.07%+35.86%-38.93%-38.93%—
How to read this: Insider Returnis the average raw return of the filer's trades over the horizon. SPY Return is what SPY did over those same windows — reference only, not a comparison. The headline alpha number is Mean Excess = Insider − SPY; green means the filer beat SPY, red means they trailed it. Win rate is the share of individual trades where the filer beat SPY. T-statvalues above 2 mean the alpha is unlikely to be chance given the sample size. "Pending" counts trades where the horizon hasn't elapsed yet; their stats are not included in the row average.
Holdings over time
MMSI · 0 shares · as of May 20, 2026
015,18530,37145,55660,741202120222023202420252026SHARES HELD
Trading cadence · quarterly flow
BUY ● SELL ●
2020
2020
2020
2021
2021
2021
2021
2022
2022
2022
2022
2023
2023
2023
2023
2024
2024
2024
2024
2025
2025
2025
2025
2026
2026
FLOW · 21 buys / 8 sellsCOVERAGE · 25 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
TMDX
TRANSMEDICS GROUP, INC.
SALE
9,624$75.06$722.4K16,642Jun 15, 2026Jun 17, 2026 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASE
19,285$2.21$42.6K26,266Jun 15, 2026Jun 17, 2026 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
SALE
19,285——0Jun 15, 2026Jun 17, 2026 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
7,500——0May 20, 2026May 21, 2026 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASE
7,500$52.17$391.3K60,741May 20, 2026May 21, 2026 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
13,750——0May 20, 2026May 21, 2026 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASE
13,750$52.17$717.3K53,241May 20, 2026May 21, 2026 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
2,922——6,981May 20, 2026May 22, 2026 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
3,457——39,491May 18, 2026May 19, 2026 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
2,134——4,059May 22, 2025May 23, 2025 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
2,152——36,034May 15, 2025May 19, 2025 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASE
25,000$50.50$1.26M46,688Feb 28, 2025Mar 3, 2025 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
25,000——0Feb 28, 2025Mar 3, 2025 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
12,806$99.95$1.28M33,882Feb 28, 2025Mar 3, 2025 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
732——1,925May 23, 2024May 28, 2024 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
1,154——1,154May 23, 2024May 28, 2024 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
2,431——21,688May 16, 2024May 20, 2024 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
18,157$76.03$1.38M19,257Mar 4, 2024Mar 5, 2024 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASE
25,000$34.40$860.0K37,414Mar 4, 2024Mar 5, 2024 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
SALE
25,000——0Mar 4, 2024Mar 5, 2024 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
1,193——1,193May 25, 2023May 30, 2023 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
1,916——1,916May 25, 2023May 30, 2023 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
2,262——12,414May 18, 2023May 22, 2023 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
13,500——13,500Jun 1, 2022Jun 6, 2022 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
3,050——10,152May 24, 2022May 26, 2022 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
2,914——7,102Jun 17, 2021Jun 21, 2021 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
13,500——13,500May 27, 2021Jun 1, 2021 ↗View →
MMSI
MERIT MEDICAL SYSTEMS INC
PURCHASEGRANT
Stock grant
4,188——4,188Jun 22, 2020Jun 24, 2020 ↗View →
TMDX
TRANSMEDICS GROUP, INC.
PURCHASEGRANT
Stock grant
15,934——15,934Jun 4, 2020Jun 5, 2020 ↗View →
Other insiders · MMSI
Loading peer insiders…
About this filer
CIK 0001708144
ROLE
Director
PRIMARY
MMSI
COMPANIES
2
ACTIVE SINCE
Jun 2020
MARKETPEEL · /INSIDER/0001708144DATA · SEC EDGAR · FORM 4 · CONSOLIDATED TAPE
FREE · DAILY · 6 AM ET

The morning brief, before the bell.

One short email. Insider buys, congressional trades, and plain-English analysis.

Feedback