Microsoft Corporation
MX ˙ BMV ˙ US5949181045
SecurityMX:MSFT / Microsoft Corporation
InstitutionCalamos Advisors LLC
Latest Disclosed Ownership2,375,507 shares
Latest Disclosed Value $ 879,341,405
Calamos Advisors LLC ownership in MSFT / Microsoft Corporation

On May 4, 2026 - Calamos Advisors LLC filed a 13F-HR form disclosing ownership of 2,375,507 shares of Microsoft Corporation (MX:MSFT) valued at $879,341,405 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 29, 2026 disclosing 2,128,249 shares of Microsoft Corporation. This represents a change in shares of 11.62% during the quarter.

Calamos Advisors LLC has a history of taking positions in derivatives of the underlying security (MSFT) in the form of stock options. The firm currently holds call options representing 55,400 of underlying shares valued at $26,792,548 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:MSFT / Microsoft 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)
2026-05-04 2026-03-31 13F MICROSOFT COM 594918104 2,375,507 247,258 11.62 879,341 -14.57 3.1015
2026-01-29 2025-12-31 13F MICROSOFT COM 594918104 2,128,249 -68,990 -3.14 1,029,264 -9.56 3.8658
2025-10-20 2025-09-30 13F MICROSOFT COM 594918104 2,197,239 -34,397 -1.54 1,138,060 2.52 4.2032
2025-08-08 2025-06-30 13F MICROSOFT COM 594918104 2,231,636 -69,947 -3.04 1,110,038 28.48 4.3692
2025-04-29 2025-03-31 13F MICROSOFT COM 594918104 2,301,583 -16,258 -0.70 863,991 -11.56 3.7608
2025-01-24 2024-12-31 13F MICROSOFT COM 594918104 2,317,841 -39,806 -1.69 976,970 -3.70 4.0858
2024-11-07 2024-09-30 13F MICROSOFT COM 594918104 2,357,647 -115,235 -4.66 1,014,496 -8.21 4.3868
2024-07-25 2024-06-30 13F MICROSOFT COM 594918104 2,472,882 -48,318 -1.92 1,105,255 4.20 4.9089
2024-05-08 2024-03-31 13F MICROSOFT COM 594918104 2,521,200 -48,557 -1.89 1,060,719 9.77 5.0254
2024-01-31 2023-12-31 13F MICROSOFT COM 594918104 2,569,757 -29,669 -1.14 966,331 17.73 4.6871
2023-10-26 2023-09-30 13F MICROSOFT COM 594918104 2,599,426 17,337 0.67 820,769 -6.66 4.2642
2023-07-28 2023-06-30 13F MICROSOFT COM 594918104 2,582,089 -130,631 -4.82 879,305 12.43 4.3504
2023-05-04 2023-03-31 13F MICROSOFT COM 594918104 2,712,720 -313,289 -10.35 782,077 7.77 3.8196
2023-01-26 2022-12-31 13F MICROSOFT COM 594918104 3,026,009 -339,640 -10.09 725,697 -7.42 3.4044
2022-10-24 2022-09-30 13F MICROSOFT COM 594918104 3,365,649 -5,223 -0.15 783,860 -9.46 3.5853
2022-08-01 2022-06-30 13F MICROSOFT COM 594918104 3,370,872 33,701 1.01 865,741 -15.86 3.7337
2022-05-03 2022-03-31 13F MICROSOFT COM 594918104 3,337,171 257,953 8.38 1,028,883 -0.65 3.8625
2022-02-01 2021-12-31 13F MICROSOFT COM 594918104 3,079,218 73,162 2.43 1,035,603 22.20 3.8720
2021-10-26 2021-09-30 13F MICROSOFT COM 594918104 3,006,056 143,497 5.01 847,467 9.28 3.7014
2021-07-22 2021-06-30 13F MICROSOFT COM 594918104 2,862,559 359,157 14.35 775,467 31.38 3.5430
2021-04-12 2021-03-31 13F MICROSOFT COM 594918104 2,503,402 68,310 2.81 590,227 8.98 3.2199
2021-01-27 2020-12-31 13F MICROSOFT COM 594918104 2,435,092 -99,535 -3.93 541,613 1.60 3.1436
2020-10-26 2020-09-30 13F MICROSOFT COM 594918104 2,534,627 -156,667 -5.82 533,108 -2.67 3.4312
2020-07-27 2020-06-30 13F MICROSOFT COM 594918104 2,691,294 -23,944 -0.88 547,705 27.90 3.8716
2020-04-28 2020-03-31 13F MICROSOFT COM 594918104 2,715,238 -910,281 -25.11 428,220 -25.10 3.3601
2020-01-15 2019-12-31 13F MICROSOFT COMMON STOCK 594918104 3,625,519 -100,887 -2.71 571,744 10.36 2.8271
2019-10-21 2019-09-30 13F MICROSOFT COMMON STOCK 594918104 3,726,406 100,847 2.78 518,082 6.67 2.8217
2019-08-07 2019-06-30 13F MICROSOFT COMMON STOCK 594918104 3,625,559 74,492 2.10 485,680 15.97 2.6967
2019-04-12 2019-03-31 13F MICROSOFT COMMON STOCK 594918104 3,551,067 128,948 3.77 418,813 20.49 2.6133
2019-01-24 2018-12-31 13F MICROSOFT COMMON STOCK 594918104 3,422,119 156,334 4.79 347,585 -6.94 2.2941
2018-10-22 2018-09-30 13F MICROSOFT COMMON STOCK 594918104 3,265,785 20,888 0.64 373,508 16.73 2.0546
2018-07-17 2018-06-30 13F MICROSOFT COMMON STOCK 594918104 3,244,897 85,801 2.72 319,979 10.98 1.9556
2018-04-13 2018-03-31 13F MICROSOFT COMMON STOCK 594918104 3,159,096 28,732 0.92 288,331 7.68 1.8762
2018-02-13 2017-12-31 13F MICROSOFT COMMON STOCK 594918104 3,130,364 -277,312 -8.14 267,771 5.49 1.3647
2017-10-25 2017-09-30 13F MICROSOFT COMMON STOCK 594918104 3,407,676 -90,316 -2.58 253,838 5.28 1.9630
2017-08-09 2017-06-30 13F MICROSOFT COMMON STOCK 594918104 3,497,992 -134,286 -3.70 241,117 0.79 1.7821
2017-04-20 2017-03-31 13F MICROSOFT COMMON STOCK 594918104 3,632,278 -83,792 -2.25 239,222 3.60 1.8835
2017-02-06 2016-12-31 13F MICROSOFT COMMON STOCK 594918104 3,716,070 -566,014 -13.22 230,917 -6.38 1.8354
2016-11-14 2016-09-30 13F MICROSOFT COMMON STOCK 594918104 4,282,084 -1,207,107 -21.99 246,648 -12.19 1.7626
2016-07-26 2016-06-30 13F MICROSOFT COMMON STOCK 594918104 5,489,191 -966,711 -14.97 280,882 -21.22 1.9705
2016-04-25 2016-03-31 13F MICROSOFT COMMON STOCK 594918104 6,455,902 -230,447 -3.45 356,559 -3.88 2.3655
2016-02-05 2015-12-31 13F MICROSOFT COMMON STOCK 594918104 6,686,349 242,492 3.76 370,959 30.07 2.3572
2015-11-10 2015-09-30 13F MICROSOFT COMMON STOCK 594918104 6,443,857 90,525 1.42 285,205 1.68 1.9655
2015-08-14 2015-06-30 13F MICROSOFT COMMON STOCK 594918104 6,353,332 695,483 12.29 280,500 21.95 1.7325
2015-05-13 2015-03-31 13F MICROSOFT COMMON STOCK 594918104 5,657,849 840,995 17.46 230,020 2.81 1.4418
2015-02-13 2014-12-31 13F MICROSOFT COMMON STOCK 594918104 4,816,854 1,570,489 48.38 223,743 48.67 1.4800
2014-11-14 2014-09-30 13F MICROSOFT COMMON STOCK 594918104 3,246,365 981,420 43.33 150,501 59.35 1.0044
2014-08-14 2014-06-30 13F MICROSOFT COMMON STOCK 594918104 2,264,945 721,120 46.71 94,448 49.25 0.5986
2014-05-16 2014-03-31 13F MICROSOFT COMMON STOCK 594918104 1,543,825 3,630 0.24 63,281 9.77 0.4044
2014-02-14 2013-12-31 13F MICROSOFT COMMON STOCK 594918104 1,540,195 1,195 0.08 57,649 12.46 0.3666
2013-11-14 2013-09-30 13F MICROSOFT COMMON STOCK 594918104 1,539,000 0 0.00 51,264 -3.53 0.3215
2013-08-12 2013-06-30 13F MICROSOFT COMMON STOCK 594918104 1,539,000 1,539,000 53,142 0.3473
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
(%)
2026-05-04 2026-03-31 13F MICROSOFT COM Call 55,400 122.49 26,793 107.75 n/a n/a n/a
2026-01-29 2025-12-31 13F MICROSOFT COM Call 24,900 -82.48 12,897 -81.75 n/a n/a n/a
2025-10-20 2025-09-30 13F MICROSOFT COM Call 142,100 6,359.09 70,682 8,467.39 n/a n/a n/a
2025-08-08 2025-06-30 13F MICROSOFT COM Call 2,200 46.67 826 30.54 n/a n/a n/a
2025-04-29 2025-03-31 13F MICROSOFT COM Call 1,500 150.00 632 144.96 n/a n/a n/a
2025-01-24 2024-12-31 13F MICROSOFT COM Call 600 258 n/a n/a n/a
2024-05-08 2024-03-31 13F MICROSOFT COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-01-31 2023-12-31 13F MICROSOFT COM Call 41,800 -21.87 13,198 -27.56 n/a n/a n/a
2023-10-26 2023-09-30 13F MICROSOFT COM Call 53,500 18,219 n/a n/a n/a
2023-01-26 2022-12-31 13F MICROSOFT COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-10-24 2022-09-30 13F MICROSOFT COM Call 43,000 10,015 n/a n/a n/a
2018-10-22 2018-09-30 13F MICROSOFT COMMON STOCK Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-07-17 2018-06-30 13F MICROSOFT COMMON STOCK Call 244,500 24,110 n/a n/a n/a
2018-04-13 2018-03-31 13F MICROSOFT COMMON STOCK Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-02-13 2017-12-31 13F MICROSOFT COMMON STOCK Call 176,100 15,064 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
(%)
2025-04-29 2025-03-31 13F MICROSOFT COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-01-24 2024-12-31 13F MICROSOFT COM Put 36,500 15,706 n/a n/a n/a
2024-11-07 2024-09-30 13F MICROSOFT COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-07-25 2024-06-30 13F MICROSOFT COM Put 18,000 7,573 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.