TransMedics Group, Inc.
US ˙ NasdaqGM ˙ US89377M1099

SecurityTMDX / TransMedics Group, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership61,601 shares
Latest Disclosed Value $ 6,123,755
Citadel Advisors Llc ownership in TMDX / TransMedics Group, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 61,601 shares of TransMedics Group, Inc. (US:TMDX) valued at $6,123,755 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 143,247 shares of TransMedics Group, Inc.. This represents a change in shares of -57.00% during the quarter. The current value of the position is $4,276,957 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (TMDX) in the form of stock options. The firm currently holds call options representing 71,600 of underlying shares valued at $7,117,756 USD and put options representing 95,400 of underlying shares valued at $9,483,714 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

TMDX / TransMedics Group, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F TRANSMEDICS GROUP COM 89377M109 61,601 -81,646 -57.00 6,124 -64.86 0.0009
2026-02-17 2025-12-31 13F TRANSMEDICS GROUP COM 89377M109 143,247 18,330 14.67 17,426 24.33 0.0026
2025-11-14 2025-09-30 13F TRANSMEDICS GROUP COM 89377M109 124,917 -31,524 -20.15 14,016 -33.15 0.0021
2025-08-14 2025-06-30 13F TRANSMEDICS GROUP COM 89377M109 156,441 -453,248 -74.34 20,965 -48.89 0.0036
2025-05-15 2025-03-31 13F TRANSMEDICS GROUP COM 89377M109 609,689 376,755 161.74 41,020 182.44 0.0078
2025-02-14 2024-12-31 13F TRANSMEDICS GROUP COM 89377M109 232,934 232,934 14,523 0.0025
2024-11-14 2024-09-30 13F TRANSMEDICS GROUP COM 89377M109 0 -78,134 -100.00 0 -100.00
2024-08-14 2024-06-30 13F TRANSMEDICS GROUP COM 89377M109 78,134 -93,700 -54.53 11,769 -7.38 0.0024
2024-05-15 2024-03-31 13F TRANSMEDICS GROUP COM 89377M109 171,834 -18,755 -9.84 12,705 -15.54 0.0025
2024-02-14 2023-12-31 13F TRANSMEDICS GROUP COM 89377M109 190,589 78,969 70.75 15,043 146.16 0.0030
2023-11-14 2023-09-30 13F TRANSMEDICS GROUP COM 89377M109 111,620 101,897 1,048.00 6,111 648.90 0.0013
2023-08-14 2023-06-30 13F TRANSMEDICS GROUP COM 89377M109 9,723 -77,300 -88.83 817 -87.62 0.0002
2023-05-15 2023-03-31 13F TRANSMEDICS GROUP COM 89377M109 87,023 -160,129 -64.79 6,590 -56.80 0.0014
2023-02-14 2022-12-31 13F TRANSMEDICS GROUP COM 89377M109 247,152 104,965 73.82 15,254 157.02 0.0036
2022-11-14 2022-09-30 13F TRANSMEDICS GROUP COM 89377M109 142,187 -29,823 -17.34 5,935 9.70 0.0014
2022-08-15 2022-06-30 13F TRANSMEDICS GROUP COM 89377M109 172,010 172,010 5,410 0.0014
2022-05-16 2022-03-31 13F TRANSMEDICS GROUP COM 89377M109 0 -13,216 -100.00 0 -100.00
2022-02-14 2021-12-31 13F TRANSMEDICS GROUP COM 89377M109 13,216 2,391 22.09 254 -29.05 0.0001
2021-11-15 2021-09-30 13F TRANSMEDICS GROUP Cmn 89377M109 10,825 -65,909 -85.89 358 -85.94 0.0001
2021-08-16 2021-06-30 13F TRANSMEDICS GROUP COM 89377M109 76,734 62,540 440.61 2,546 332.26 0.0006
2021-05-21 2021-03-31 13F/A-1 TRANSMEDICS GROUP COM 89377M109 14,194 14,194 589 0.0001
2021-05-17 2021-03-31 13F TRANSMEDICS GROUP COM 89377M109 14,194 14,194 589 0.0001
2021-02-16 2020-12-31 13F TRANSMEDICS GROUP COM 89377M109 0 -62,951 -100.00 0 -100.00
2020-11-16 2020-09-30 13F TRANSMEDICS GROUP COM 89377M109 62,951 62,951 868 0.0002
2020-08-14 2020-06-30 13F TRANSMEDICS GROUP Cmn 89377M109 0 -11,351 -100.00 0 -100.00
2020-05-15 2020-03-31 13F TRANSMEDICS GROUP Cmn 89377M109 11,351 -4,009 -26.10 137 -53.08 0.0001
2020-02-14 2019-12-31 13F TRANSMEDICS GROUP Cmn 89377M109 15,360 -32,565 -67.95 292 -74.34 0.0001
2019-11-14 2019-09-30 13F TRANSMEDICS GROUP Cmn 89377M109 47,925 3,735 8.45 1,138 -11.16 0.0005
2019-08-14 2019-06-30 13F TRANSMEDICS GROUP Cmn 89377M109 44,190 44,190 1,281 0.0006
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F TRANSMEDICS GROUP COM Call 71,600 -14.66 7,118 -30.27 n/a n/a n/a
2026-02-17 2025-12-31 13F TRANSMEDICS GROUP COM Call 83,900 -76.57 10,206 -74.60 n/a n/a n/a
2025-11-14 2025-09-30 13F TRANSMEDICS GROUP COM Call 358,100 -12.64 40,179 -26.86 n/a n/a n/a
2025-08-14 2025-06-30 13F TRANSMEDICS GROUP COM Call 409,900 40.76 54,931 180.38 n/a n/a n/a
2025-05-15 2025-03-31 13F TRANSMEDICS GROUP COM Call 291,200 23.13 19,592 32.87 n/a n/a n/a
2025-02-14 2024-12-31 13F TRANSMEDICS GROUP COM Call 236,500 22.16 14,746 -51.49 n/a n/a n/a
2024-11-14 2024-09-30 13F TRANSMEDICS GROUP COM Call 193,600 25.71 30,395 31.04 n/a n/a n/a
2024-08-14 2024-06-30 13F TRANSMEDICS GROUP COM Call 154,000 258.14 23,195 629.63 n/a n/a n/a
2024-05-15 2024-03-31 13F TRANSMEDICS GROUP COM Call 43,000 38.71 3,179 29.97 n/a n/a n/a
2024-02-14 2023-12-31 13F TRANSMEDICS GROUP COM Call 31,000 -34.87 2,447 -6.14 n/a n/a n/a
2023-11-14 2023-09-30 13F TRANSMEDICS GROUP COM Call 47,600 115.38 2,606 40.49 n/a n/a n/a
2023-08-14 2023-06-30 13F TRANSMEDICS GROUP COM Call 22,100 -7.53 1,856 2.54 n/a n/a n/a
2023-05-15 2023-03-31 13F TRANSMEDICS GROUP COM Call 23,900 -16.14 1,810 2.84 n/a n/a n/a
2023-02-14 2022-12-31 13F TRANSMEDICS GROUP COM Call 28,500 -22.76 1,759 14.22 n/a n/a n/a
2022-11-14 2022-09-30 13F TRANSMEDICS GROUP COM Call 36,900 126.38 1,540 200.19 n/a n/a n/a
2022-08-15 2022-06-30 13F TRANSMEDICS GROUP COM Call 16,300 31.45 513 53.59 n/a n/a n/a
2022-05-16 2022-03-31 13F TRANSMEDICS GROUP COM Call 12,400 -25.75 334 4.38 n/a n/a n/a
2022-02-14 2021-12-31 13F TRANSMEDICS GROUP COM Call 16,700 -80.49 320 -88.70 n/a n/a n/a
2021-11-15 2021-09-30 13F TRANSMEDICS GROUP Cmn Call 85,600 179.74 2,833 179.11 n/a n/a n/a
2021-08-16 2021-06-30 13F TRANSMEDICS GROUP COM Call 30,600 13.75 1,015 -9.05 n/a n/a n/a
2021-05-21 2021-03-31 13F/A TRANSMEDICS GROUP COM Call 26,900 1,116 n/a n/a n/a
2021-05-17 2021-03-31 13F TRANSMEDICS GROUP COM Call 26,900 1,116 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F TRANSMEDICS GROUP COM Put 95,400 -22.31 9,484 -36.52 n/a n/a n/a
2026-02-17 2025-12-31 13F TRANSMEDICS GROUP COM Put 122,800 -48.90 14,939 -44.59 n/a n/a n/a
2025-11-14 2025-09-30 13F TRANSMEDICS GROUP COM Put 240,300 -14.21 26,962 -28.17 n/a n/a n/a
2025-08-14 2025-06-30 13F TRANSMEDICS GROUP COM Put 280,100 3.09 37,536 105.35 n/a n/a n/a
2025-05-15 2025-03-31 13F TRANSMEDICS GROUP COM Put 271,700 -11.30 18,280 -4.28 n/a n/a n/a
2025-02-14 2024-12-31 13F TRANSMEDICS GROUP COM Put 306,300 201.18 19,098 19.61 n/a n/a n/a
2024-11-14 2024-09-30 13F TRANSMEDICS GROUP COM Put 101,700 107.98 15,967 116.78 n/a n/a n/a
2024-08-14 2024-06-30 13F TRANSMEDICS GROUP COM Put 48,900 -18.77 7,365 65.47 n/a n/a n/a
2024-05-15 2024-03-31 13F TRANSMEDICS GROUP COM Put 60,200 423.48 4,451 390.74 n/a n/a n/a
2024-02-14 2023-12-31 13F TRANSMEDICS GROUP COM Put 11,500 -44.98 908 -20.72 n/a n/a n/a
2023-11-14 2023-09-30 13F TRANSMEDICS GROUP COM Put 20,900 43.15 1,144 -6.69 n/a n/a n/a
2023-08-14 2023-06-30 13F TRANSMEDICS GROUP COM Put 14,600 11.45 1,226 23.59 n/a n/a n/a
2023-05-15 2023-03-31 13F TRANSMEDICS GROUP COM Put 13,100 29.70 992 59.23 n/a n/a n/a
2023-02-14 2022-12-31 13F TRANSMEDICS GROUP COM Put 10,100 -50.73 623 -27.22 n/a n/a n/a
2022-11-14 2022-09-30 13F TRANSMEDICS GROUP COM Put 20,500 856 n/a n/a n/a
2022-08-15 2022-06-30 13F TRANSMEDICS GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-16 2022-03-31 13F TRANSMEDICS GROUP COM Put 8,600 -56.12 232 -38.30 n/a n/a n/a
2022-02-14 2021-12-31 13F TRANSMEDICS GROUP COM Put 19,600 -29.24 376 -59.00 n/a n/a n/a
2021-11-15 2021-09-30 13F TRANSMEDICS GROUP Cmn Put 27,700 -24.93 917 -25.08 n/a n/a n/a
2021-08-16 2021-06-30 13F TRANSMEDICS GROUP COM Put 36,900 -49.38 1,224 -59.54 n/a n/a n/a
2021-05-21 2021-03-31 13F/A TRANSMEDICS GROUP COM Put 72,900 113.78 3,025 345.51 n/a n/a n/a
2021-05-17 2021-03-31 13F TRANSMEDICS GROUP COM Put 72,900 3,025 n/a n/a n/a
2021-02-16 2020-12-31 13F TRANSMEDICS GROUP COM Put 34,100 679 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.