undamentalytics Newsletter

Tandem Diabetes Care Inc insider trading

Every open-market purchase and sale by Tandem Diabetes Care Inc's officers, directors and largest shareholders since November 4, 2021, and what the share price did next.

No insider has bought shares on the open market in five years.

Insider purchase Insider sale Marker size reflects trade value. Weekly closes adjusted for splits; may be delayed.
Tandem Diabetes Care Inc insider open-market trades
DateInsiderTrade SharesPriceValue 1M after 3M after 6M after

From insiders' Form 4 filings with the SEC: open-market purchases and sales only (awards, option exercises and shares withheld for tax are excluded), combined to one line per insider per day. "Plan" marks trades the filing says were made under a pre-set Rule 10b5-1 trading plan, which are scheduled in advance. Price changes run from the close on the trade date; hover a figure for the change relative to the S&P 500. Past moves don't predict future ones.

Does following Tandem Diabetes Care Inc’s insiders pay?

From December 15, 2014 to August 11, 2025, 16 insiders reported 26 open-market purchases and 51 sales not made under a pre-set plan in Tandem Diabetes Care Inc. Twelve months after each purchase was reported, the shares were +12.1% against the S&P 500 on average (median +26.4%), over 18 purchases with a full year of prices; 61% beat the index. After sales, the shares moved −15.7% against the index over 12 months (a negative figure means selling was the right call). That rests on fewer than 20 purchases, too few to read much into. Buying each purchase the day after it was reported, an equal amount each, held 12 months or until that insider reported a sale, would have turned $10,000 on December 16, 2014 into $1,725 by November 2, 2026, −13.8% a year. It held shares 63% of the time; the S&P 500 on those same days, with Treasury bills otherwise, made $31,840 (+10.3% a year), and held throughout $46,646 (+13.9%).

$0$20.0k$40.0k 2014201620182020202220242026 $46.6k$31.8k$1.7k
Copying Tandem Diabetes Care Inc's insidersS&P 500, same days investedS&P 500, held throughout $10,000 copying every open-market purchase by Tandem Diabetes Care Inc's insiders from December 16, 2014, before costs and taxes, marked weekly. Uninvested money earns the Treasury bill rate; the portfolio held shares 63% of the time.
Tandem Diabetes Care Inc: each insider's record
InsiderRolePurchases12 months after their purchasesBeat the S&P 500Sales12 months after their salesLatest report
Blickenstaff Kim D Executive Chairman 3 — — 23 −9.8% (23) November 22, 2024
Allen Dick Director 6 −8.9% (4) 50% 6 −2.8% (6) June 3, 2024
Berger David B EVP & Chief Operating Officer 0 — — 8 −39.0% (8) March 7, 2023
Sheridan John F PRESIDENT & CEO 2 +13.3% (2) 50% 5 −38.0% (5) August 11, 2025
Greene Howard E Jr Director 1 — — 4 +13.6% (4) August 6, 2019
Vosseller Leigh EVP & CHIEF FINANCIAL OFFICER 4 +19.8% (4) 75% 0 — August 11, 2025
Twomey Christopher J Director 1 — — 2 −35.2% (2) May 10, 2022
Howell Peyton R Director 2 −7.1% (2) 50% 0 — May 19, 2023
Mcgroddy-Goetz Kathleen Director 1 +64.7% (1) 100% 1 −54.3% (1) September 19, 2023
Valencia Richard P. Director 2 +59.6% (2) 100% 0 — November 7, 2018
Cahill Edward L Director 0 — — 1 +48.4% (1) August 14, 2019
Hansen Brian B EVP & CHIEF COMMERCIAL OFFICER 0 — — 1 −32.9% (1) August 4, 2020
Hansen Shannon Marie Chief Legal Officer 1 +26.4% (1) 100% 0 — November 13, 2023
Kyrillos Jean-Claude EVP & Chief Operating Officer 1 −4.9% (1) 0% 0 — March 11, 2025
Novara Mark David EVP & CHIEF COMMERCIAL OFFICER 1 −43.4% (1) 0% 0 — November 19, 2024
Roeder Douglas A Director 1 — — 0 — February 13, 2018

Moves are the shares’ return including dividends minus the S&P 500’s, from the close on the first trading day after each report; the number of trades with a finished 12-month window is in brackets. Green means the trade went the insider’s way (a purchase ahead of the index, a sale followed by the shares trailing it). A trade reported both by a director or officer and by a fund or company they are linked to counts once here, under the person. Purchases count only where the share price actually traded was at least $5. These figures describe what the shares did, not why anyone traded. Insiders across all companies.

When several insiders traded Tandem Diabetes Care Inc

Months when 2 or more insiders became net buyers, or 3 or more net sellers, of Tandem Diabetes Care Inc in reports dated in the 91 days before the month end, and how the stock did against the S&P 500 from that month end. After the 3 buying crowds with six months of prices, it averaged +63.6% against the index. After 6 selling crowds, +11.8%. One company's history is too short to judge by; the test across every company is the better guide.

MonthCrowd3 months on, vs S&P 5006 months12 months
August 29, 20252 buying+61.7%+83.7%+50.7%
November 30, 20234 buying+41.2%+140.3%+26.6%
May 31, 20233 buying+1.4%−33.3%+69.1%
May 31, 20224 selling−29.5%−37.9%−67.9%
May 28, 20213 selling+21.6%+41.9%−17.2%
August 31, 20203 selling−20.8%−30.3%−31.7%
September 30, 20193 selling−9.0%+21.3%+76.8%
March 29, 20194 selling−2.6%−13.0%+12.6%
November 30, 20183 selling+70.9%+89.1%+71.2%

Colours show whether the crowd was right: green when buyers were followed by a rise above the index, or sellers by a fall below it. Total returns from the month end; past patterns are not a forecast.

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