Boston Scientific Corporation
MX ˙ BMV ˙ FR0010424135
SecurityMX:BSX / Boston Scientific Corporation
InstitutionBalyasny Asset Management Llc
Latest Disclosed Ownership1,356,133 shares
Latest Disclosed Value $ 85,097,346
Balyasny Asset Management Llc ownership in BSX / Boston Scientific Corporation

On May 15, 2026 - Balyasny Asset Management Llc filed a 13F-HR form disclosing ownership of 1,356,133 shares of Boston Scientific Corporation (MX:BSX) valued at $85,097,346 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 2,481,749 shares of Boston Scientific Corporation. This represents a change in shares of -45.36% during the quarter.

Balyasny Asset Management Llc has a history of taking positions in derivatives of the underlying security (BSX) in the form of stock options. The firm currently holds call options representing 23,500 of underlying shares valued at $1,474,625 USD and put options representing 0 of underlying shares valued at $0 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.

MX:BSX / Boston Scientific Corporation 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 BOSTON SCIENTIFIC COM 101137107 1,356,133 -1,125,616 -45.36 85,097 -64.04 0.1022
2026-02-17 2025-12-31 13F BOSTON SCIENTIFIC COM 101137107 2,481,749 927,848 59.71 236,635 55.98 0.3004
2025-11-14 2025-09-30 13F BOSTON SCIENTIFIC COM 101137107 1,553,901 48,988 3.26 151,707 -6.15 0.1923
2025-08-14 2025-06-30 13F BOSTON SCIENTIFIC COM 101137107 1,504,913 -333,266 -18.13 161,643 -12.83 0.2434
2025-05-15 2025-03-31 13F BOSTON SCIENTIFIC COM 101137107 1,838,179 71,571 4.05 185,435 17.52 0.3066
2025-02-14 2024-12-31 13F BOSTON SCIENTIFIC COM 101137107 1,766,608 -1,688,996 -48.88 157,793 -45.51 0.2350
2024-11-14 2024-09-30 13F BOSTON SCIENTIFIC COM 101137107 3,455,604 539,531 18.50 289,580 28.95 0.4723
2024-08-14 2024-06-30 13F BOSTON SCIENTIFIC COM 101137107 2,916,073 1,322,739 83.02 224,567 105.78 0.3930
2024-05-13 2024-03-31 13F BOSTON SCIENTIFIC COM 101137107 1,593,334 260,778 19.57 109,127 41.66 0.1906
2024-02-14 2023-12-31 13F BOSTON SCIENTIFIC COM 101137107 1,332,556 1,324,980 17,489.18 77,035 19,158.75 0.1447
2023-11-14 2023-09-30 13F BOSTON SCIENTIFIC COM 101137107 7,576 -11,336 -59.94 400 -60.86 0.0008
2023-08-14 2023-06-30 13F BOSTON SCIENTIFIC COM 101137107 18,912 -575,106 -96.82 1,023 -96.56 0.0022
2023-05-15 2023-03-31 13F BOSTON SCIENTIFIC COM 101137107 594,018 594,018 29,719 0.0745
2023-02-14 2022-12-31 13F BOSTON SCIENTIFIC COM 101137107 0 -2,347,335 -100.00 0 -100.00
2022-11-15 2022-09-30 13F BOSTON SCIENTIFIC COM 101137107 2,347,335 1,163,565 98.29 90,912 106.06 0.2789
2022-08-15 2022-06-30 13F BOSTON SCIENTIFIC COM 101137107 1,183,770 707,487 148.54 44,119 109.14 0.1436
2022-05-16 2022-03-31 13F BOSTON SCIENTIFIC COM 101137107 476,283 476,283 21,095 0.0665
2022-02-14 2021-12-31 13F BOSTON SCIENTIFIC COM 101137107 0 -2,155,328 -100.00 0 -100.00
2021-12-01 2021-09-30 13F/A-1 BOSTON SCIENTIFIC COM 101137107 2,155,328 423,352 24.44 93,520 26.28 0.3895
2021-11-15 2021-09-30 13F BOSTON SCIENTIFIC COM 101137107 2,155,328 423,352 93,520 0.3847
2021-08-16 2021-06-30 13F BOSTON SCIENTIFIC COM 101137107 1,731,976 1,731,976 74,059 0.3507
2020-11-16 2020-09-30 13F BOSTON SCIENTIFIC COM 101137107 0 -148,178 -100.00 0 -100.00
2020-08-14 2020-06-30 13F BOSTON SCIENTIFIC COM 101137107 148,178 -2,031,758 -93.20 5,203 -92.69 0.0451
2020-05-15 2020-03-31 13F BOSTON SCIENTIFIC COM 101137107 2,179,936 1,853,465 567.73 71,131 381.82 0.8436
2020-02-14 2019-12-31 13F BOSTON SCIENTIFIC COM 101137107 326,471 326,471 -85.02 14,763 -79.25 0.0878
2019-08-14 2019-06-30 13F BOSTON SCIENTIFIC COM 101137107 0 -616,675 -100.00 0 -100.00
2019-05-15 2019-03-31 13F BOSTON SCIENTIFIC COM 101137107 616,675 616,675 23,668 0.1574
2019-02-14 2018-12-31 13F BOSTON SCIENTIFIC COM 101137107 0 -468,618 -100.00 0 -100.00
2018-11-14 2018-09-30 13F BOSTON SCIENTIFIC COM 101137107 468,618 -327,892 -41.17 18,042 -30.73 0.0819
2018-08-14 2018-06-30 13F BOSTON SCIENTIFIC COM 101137107 796,510 668,139 520.48 26,046 642.69 0.1182
2018-05-15 2018-03-31 13F BOSTON SCIENTIFIC COM 101137107 128,371 -808,738 -86.30 3,507 -84.90 0.0147
2018-02-14 2017-12-31 13F Boston Scientific Common Stock 101137107 937,109 -44,815 -4.56 23,231 -18.89 0.0726
2017-11-14 2017-09-30 13F Boston Scientific Common Stock 101137107 981,924 -917,642 -48.31 28,643 -45.60 0.1122
2017-08-14 2017-06-30 13F Boston Scientific Common Stock 101137107 1,899,566 1,838,876 3,029.95 52,656 3,389.46 0.2171
2017-05-15 2017-03-31 13F Boston Scientific Common Stock 101137107 60,690 -14,989 -19.81 1,509 -7.82 0.0070
2017-02-14 2016-12-31 13F Boston Scientific Common Stock 101137107 75,679 -2,597,698 -97.17 1,637 -97.38 0.0088
2016-08-15 2016-06-30 13F Boston Scientific Common Stock 101137107 2,673,377 2,673,377 3,432.52 62,477 3,716.55 0.4047
2016-05-16 2016-03-31 13F Boston Scientific Common Stock 101137107 0 -811,023 -100.00 0 -100.00
2016-02-16 2015-12-31 13F Boston Scientific Common Stock 101137107 811,023 318,423 64.64 14,955 85.00 0.1038
2015-11-16 2015-09-30 13F Boston Scientific Common Stock 101137107 492,600 492,600 -39.26 8,084 -45.94 0.0597
2014-02-14 2013-12-31 13F Boston Scientific Common Stock 101137107 0 -1,130,172 -100.00 0 -100.00
2013-11-14 2013-09-30 13F Boston Scientific Common Stock 101137107 1,130,172 126,292 12.58 13,268 42.57 0.1790
2013-08-14 2013-06-30 13F Boston Scientific Common Stock 101137107 1,003,880 1,003,880 9,306 0.1562
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 BOSTON SCIENTIFIC COM Call 23,500 -57.66 1,475 -72.14 n/a n/a n/a
2026-02-17 2025-12-31 13F BOSTON SCIENTIFIC COM Call 55,500 -79.85 5,292 -80.32 n/a n/a n/a
2025-11-14 2025-09-30 13F BOSTON SCIENTIFIC COM Call 275,400 26,887 n/a n/a n/a
2025-08-14 2025-06-30 13F BOSTON SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F BOSTON SCIENTIFIC COM Call 4,500 -82.76 454 -80.57 n/a n/a n/a
2025-02-14 2024-12-31 13F BOSTON SCIENTIFIC COM Call 26,100 8.30 2,331 15.45 n/a n/a n/a
2024-11-14 2024-09-30 13F BOSTON SCIENTIFIC COM Call 24,100 14.22 2,020 24.32 n/a n/a n/a
2024-08-14 2024-06-30 13F BOSTON SCIENTIFIC COM Call 21,100 -49.88 1,625 -43.67 n/a n/a n/a
2024-05-13 2024-03-31 13F BOSTON SCIENTIFIC COM Call 42,100 0.00 2,883 18.50 n/a n/a n/a
2024-02-14 2023-12-31 13F BOSTON SCIENTIFIC COM Call 42,100 2,434 n/a n/a n/a
2023-02-14 2022-12-31 13F BOSTON SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-15 2022-09-30 13F BOSTON SCIENTIFIC COM Call 390,000 -85.17 15,105 -84.59 n/a n/a n/a
2022-08-15 2022-06-30 13F BOSTON SCIENTIFIC COM Call 2,630,000 839.29 98,020 690.42 n/a n/a n/a
2022-05-16 2022-03-31 13F BOSTON SCIENTIFIC COM Call 280,000 12,401 n/a n/a n/a
2021-12-01 2021-09-30 13F/A BOSTON SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F BOSTON SCIENTIFIC COM Call 0 0 n/a n/a n/a
2021-08-16 2021-06-30 13F BOSTON SCIENTIFIC COM Call 17,800 761 n/a n/a n/a
2021-05-17 2021-03-31 13F BOSTON SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-16 2020-12-31 13F BOSTON SCIENTIFIC COM Call 100,000 -66.67 3,595 -68.64 n/a n/a n/a
2020-11-16 2020-09-30 13F BOSTON SCIENTIFIC COM Call 300,000 100.00 11,463 117.64 n/a n/a n/a
2020-08-14 2020-06-30 13F BOSTON SCIENTIFIC COM Call 150,000 -50.00 5,267 -54.05 n/a n/a n/a
2019-02-14 2018-12-31 13F BOSTON SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-11-14 2018-09-30 13F BOSTON SCIENTIFIC COM Call 475,000 10.47 17,808 26.65 n/a n/a n/a
2018-08-14 2018-06-30 13F BOSTON SCIENTIFIC COM Call 430,000 14,061 n/a n/a n/a
2017-11-14 2017-09-30 13F Boston Scientific Common Stock Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-08-14 2017-06-30 13F Boston Scientific Common Stock Call 400,000 0.00 11,088 18.61 n/a n/a n/a
2016-08-15 2016-06-30 13F Boston Scientific Common Stock Call 400,000 9,348 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 BOSTON SCIENTIFIC COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2026-02-17 2025-12-31 13F BOSTON SCIENTIFIC COM Put 84,200 109.45 8,028 104.59 n/a n/a n/a
2025-11-14 2025-09-30 13F BOSTON SCIENTIFIC COM Put 40,200 2.81 3,925 -6.55 n/a n/a n/a
2025-08-14 2025-06-30 13F BOSTON SCIENTIFIC COM Put 39,100 -28.39 4,200 -23.77 n/a n/a n/a
2025-05-15 2025-03-31 13F BOSTON SCIENTIFIC COM Put 54,600 -42.28 5,508 -34.81 n/a n/a n/a
2025-02-14 2024-12-31 13F BOSTON SCIENTIFIC COM Put 94,600 27.32 8,450 35.71 n/a n/a n/a
2024-11-14 2024-09-30 13F BOSTON SCIENTIFIC COM Put 74,300 3.19 6,226 12.30 n/a n/a n/a
2024-08-14 2024-06-30 13F BOSTON SCIENTIFIC COM Put 72,000 -36.84 5,545 -28.99 n/a n/a n/a
2024-05-13 2024-03-31 13F BOSTON SCIENTIFIC COM Put 114,000 0.00 7,808 18.47 n/a n/a n/a
2024-02-14 2023-12-31 13F BOSTON SCIENTIFIC COM Put 114,000 -56.15 6,590 -52.00 n/a n/a n/a
2023-11-14 2023-09-30 13F BOSTON SCIENTIFIC COM Put 260,000 13,728 n/a n/a n/a
2021-12-01 2021-09-30 13F/A BOSTON SCIENTIFIC COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F BOSTON SCIENTIFIC COM Put 0 0 n/a n/a n/a
2021-08-16 2021-06-30 13F BOSTON SCIENTIFIC COM Put 19,000 812 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.