John Overdeck’s Tandem Diabetes Care TNDM Stock Holding History

John Overdeck’s Portfolio TNDM Stock Details TNDM Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2022 Q1	–	Sell	-8,900	Closed	-$1.34M	–	4266
2021 Q4	$1.34M	Buy	8,900 +4,900	+123%	+$661K	﹤0.01%	2296
2021 Q3	$478K	Sell	4,000 -10,000	-71%	-$1.1M	﹤0.01%	3307
2021 Q2	$1.36M	Buy	14,000 +2,100	+18%	+$187K	﹤0.01%	2205
2021 Q1	$1.05M	Sell	11,900 -25,800	-68%	-$2.4M	﹤0.01%	2267
2020 Q4	$3.61M	Buy	37,700 +1,600	+4%	+$165K	0.01%	1119
2020 Q3	$4.1M	Buy	36,100 +19,800	+121%	+$2.08M	0.01%	891
2020 Q2	$1.61M	Sell	16,300 -10,600	-39%	-$846K	0.01%	1210
2020 Q1	$1.73M	Buy	26,900 +16,900	+169%	+$1.18M	0.01%	1046
2019 Q4	$596K	Sell	10,000 -4,100	-29%	-$253K	﹤0.01%	2643
2019 Q3	$832K	Sell	14,100 -11,600	-45%	-$740K	﹤0.01%	2131
2019 Q2	$1.66M	Buy	+25,700	New	+$1.66M	0.01%	1576
2019 Q1	–	Sell	-17,000	Closed	-$645K	–	3472
2018 Q4	$645K	Buy	+17,000	New	+$600K	﹤0.01%	1943

Other funds holding TNDM

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Sessa Capital New York $5.98B AUM 99.85% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

FLAM

First Light Asset Management Edina, Minnesota $1.65B AUM 203.21% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

GKIM

GW&K Investment Management Boston, Massachusetts $12.8B AUM 48.82% 1-Year Est. Return

Jennison Associates New York $167B AUM 44.17% 1-Year Est. Return

PIM

Paradice Investment Management Denver, Colorado $627M AUM 43.41% 1-Year Est. Return

Jacobs Levy Equity Management Florham Park, New Jersey $27.8B AUM 46.46% 1-Year Est. Return

John Overdeck's TNDM Position: Q2 2026 in Review

John Overdeck reduced its Tandem Diabetes Care (TNDM) stake by 70% in Q2 2026, selling an estimated $22.8M and leaving 558,409 shares worth $8.43M. The position accounts for 0.01% of the portfolio, ranked #1652.

John Overdeck first reported a position in TNDM in Q1 2014 and has held it in 30 quarters since. The position peaked at $56.7M in Q1 2019. 272 funds tracked by Wall St. Rank hold TNDM as of Q2 2026.

John Overdeck held 558,409 shares of Tandem Diabetes Care worth $8.43M as of Q2 2026.
John Overdeck sold 1,305,785 Tandem Diabetes Care shares in Q2 2026, an estimated $22.8M.
Tandem Diabetes Care made up 0.01% of John Overdeck's portfolio in Q2 2026, its #1652 holding.
John Overdeck first reported a position in Tandem Diabetes Care in Q1 2014 and has held it in 30 quarters since.
John Overdeck's Tandem Diabetes Care position peaked at $56.7M in Q1 2019.
272 funds tracked by Wall St. Rank held Tandem Diabetes Care as of Q2 2026.

Based on Two Sigma Investments's 13F filing for Q2 2026, filed 14 Aug 2026.