L3VLUP
ProSign in

MD in the 13F filings

Mednax Inc · CUSIP 58502B106

Sector · Health care services and research
Quarter
Q2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024Q2 2024Q1 2024Q4 2023Q3 2023
Quarter end
31 Mar 2026
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 12 May 2026
Managers listing it
17
at least, of 95 tracked, among listed positions
Comparable managers
91
filed both Q4 2025 and Q1 2026; 2 listed it in both
Shares listed
8,394,431
combined, among listed positions
Reported value
$180m
combined, at the quarter end

AllianceBernstein LP. Values in this filing are at the previous quarter end's prices; its share count is the quarter end's.

Among the 91 comparable managers: 10 buyers (opened or added shares) and 11 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was -515,057.

Managers listing MD in Q1 2026

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q4 2025, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

17 of 17 holders

ActionFiling
Fidelity (FMR LLC)2,267,434$49munder 0.1%Trimmed-161,34915 May 2026 (the filing on sec.gov)
D. E. Shaw & Co.1,708,433$37munder 0.1%Trimmed-143,78615 May 2026 (the filing on sec.gov)
Renaissance Technologies LLC1,532,300$33m0.05%Added+174,60014 May 2026 (the filing on sec.gov)
Invesco Ltd922,177$20munder 0.1%Trimmed-168,47812 May 2026 (the filing on sec.gov)
AllianceBernstein LP770,715$16munder 0.1%Trimmed-45,04015 May 2026 (the filing on sec.gov)
AQR Capital Management LLC560,569$12munder 0.1%Added+8,74615 May 2026 (the filing on sec.gov)
Jane Street Group LLC218,655$4.7munder 0.1%Added+107,88012 May 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc98,873$2.1munder 0.1%Added+12,30115 May 2026 (the filing on sec.gov)
Citadel Advisors LLC73,000$1.6munder 0.1%Trimmed-5,06015 May 2026 (the filing on sec.gov)
Susquehanna International Group LLP56,210$1.2munder 0.1%Added+14,51515 May 2026 (the filing on sec.gov)
Winton Group Ltd52,703$1.1munder 0.1%Added+1,88212 May 2026 (the filing on sec.gov)
Two Sigma Investments LP48,372$1.0munder 0.1%Added+8,70015 May 2026 (the filing on sec.gov)
Janus Henderson Group Ltd34,264$733kunder 0.1%Held018 May 2026 (the filing on sec.gov)
Freestone Grove Partners LP19,068$408kunder 0.1%Newnew15 May 2026 (the filing on sec.gov)
Neuberger Berman Group LLC11,215$240kunder 0.1%Newnew27 Oct 2026 (the filing on sec.gov)
Balyasny Asset Management LLC10,860$232kunder 0.1%Newnew15 May 2026 (the filing on sec.gov)
Brevan Howard Capital Management LP9,583$205kunder 0.1%Trimmed-17,57615 May 2026 (the filing on sec.gov)

Largest increases and reductions, by shares

Q4 2025 to Q1 2026, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (3)

Exited (5)

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
2 in Q3 2024 to 2 in Q2 2026

Tracked managers listing it, at least.

051015split2014201620182020202220242026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
MD by quarter
QuarterHoldersReported valueBuyersSellers
Q2 20137$841mn.a.n.a.
Q3 20136$879mn.a.n.a.
Q4 2013 (split)7$887mn.a.n.a.
Q1 20148$1.1bnn.a.n.a.
Q2 20148$613mn.a.n.a.
Q3 20149$577mn.a.n.a.
Q4 20148$626mn.a.n.a.
Q1 20159$741mn.a.n.a.
Q2 20156$744mn.a.n.a.
Q3 201511$1.0bnn.a.n.a.
Q4 20157$1.2bnn.a.n.a.
Q1 20169$1.1bnn.a.n.a.
Q2 20165$1.0bnn.a.n.a.
Q3 20165$1.0bnn.a.n.a.
Q4 20164$1.1bnn.a.n.a.
Q1 20174$1.2bnn.a.n.a.
Q2 20174$848mn.a.n.a.
Q3 20174$498mn.a.n.a.
Q4 20177$751mn.a.n.a.
Q1 20186$709mn.a.n.a.
Q2 20188$540mn.a.n.a.
Q3 201810$647mn.a.n.a.
Q4 20189$414mn.a.n.a.
Q1 201910$286mn.a.n.a.
Q2 20197$160mn.a.n.a.
Q3 20198$198mn.a.n.a.
Q4 201910$255mn.a.n.a.
Q1 20205$127mn.a.n.a.
Q2 20203$159mn.a.n.a.
Q3 20204$154mn.a.n.a.
Q4 20207$380mn.a.n.a.
Q1 20215$397mn.a.n.a.
Q2 20218$502mn.a.n.a.
Q3 20215$360mn.a.n.a.
Q4 20214$364mn.a.n.a.
Q1 20222$311mn.a.n.a.
Q2 20223$282mn.a.n.a.
Q3 20223$206mn.a.n.a.
Q4 20223$178mn.a.n.a.
Q1 20233$123mn.a.n.a.
Q2 20233$125mn.a.n.a.
Q3 20232$98mn.a.n.a.
Q4 20232$74m20
Q1 20242$82m20
Q2 20241$985k10
Q3 20242$95m11
Q4 20242$98m02
Q1 20252$101m02
Q2 20251$1.1m01
Q3 20253$4.8m30
Q4 20253$31m914
Q1 20261$33m1011
Q2 20262$34m811

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

MD and UNH →MD and ELV →MD and CI →Choose a stock to compare with MD →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own MD, latest filings →Back to the 13F Explorer →